[HTC U11  ROMs, Kernels, Recoveries, & Other Develo] rajackar:
It took me a while but I'm back with the results ;)

I managed to dig this up in the logcat:

03-19 11:25:44.837 4478 32014 I CastNearbyRequest: [FilterRequest] Http request sent to url: https://cast.google.com/cast/nearby/search
03-19 11:25:44.850 4478 32014 D libc : [NET] android_getaddrinfo_proxy get netid:0
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[0]=getaddrinfo
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[1]=cast.google.com
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[2]=^
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[3]=1024
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[4]=0
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[5]=1
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[6]=0
03-19 11:25:44.850 2924 3253 D DnsProxyListener: argv[7]=0
03-19 11:25:44.850 2924 3253 D DnsProxyListener: GetAddrInfoHandler for cast.google.com / [nullservice] / {104,786536,104,917608,10023}
03-19 11:25:44.853 2924 3816 D DnsProxyListener: GetAddrInfoHandler, now for cast.google.com / (null) / {104,786536,104,917608,10023}
03-19 11:25:44.865 3374 3805 D libc : [NET] android_getaddrinfo_proxy get netid:0
03-19 11:25:44.865 3374 3803 D libc : [NET] android_getaddrinfo_proxy get netid:0
03-19 11:25:44.865 3374 3796 D libc : [NET] android_getaddrinfo_proxy get netid:0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[0]=getaddrinfo
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[1]=spclient.wg.spotify.com
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[2]=^
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[3]=1024
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[4]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[5]=1
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[6]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[7]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: GetAddrInfoHandler for spclient.wg.spotify.com / [nullservice] / {104,104,104,917608,10132}
03-19 11:25:44.865 2924 3817 D DnsProxyListener: GetAddrInfoHandler, now for spclient.wg.spotify.com / (null) / {104,104,104,917608,10132}
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[0]=getaddrinfo
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[1]=spclient.wg.spotify.com
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[2]=^
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[3]=1024
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[4]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[5]=1
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[6]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[7]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: GetAddrInfoHandler for spclient.wg.spotify.com / [nullservice] / {104,104,104,917608,10132}
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[0]=getaddrinfo
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[1]=spclient.wg.spotify.com
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[2]=^
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[3]=1024
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[4]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[5]=1
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[6]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: argv[7]=0
03-19 11:25:44.865 2924 3253 D DnsProxyListener: GetAddrInfoHandler for spclient.wg.spotify.com / [nullservice] / {104,104,104,917608,10132}
03-19 11:25:44.866 2924 3818 D DnsProxyListener: GetAddrInfoHandler, now for spclient.wg.spotify.com / (null) / {104,104,104,917608,10132}
03-19 11:25:44.867 2924 3816 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:25:44.867 2924 3826 D DnsProxyListener: GetAddrInfoHandler, now for spclient.wg.spotify.com / (null) / {104,104,104,917608,10132}
03-19 11:25:44.868 3374 3610 D libc : [NET] android_getaddrinfo_proxy get netid:0
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[0]=getaddrinfo
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[1]=reports.crashlytics.com
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[2]=^
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[3]=1024
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[4]=0
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[5]=1
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[6]=0
03-19 11:25:44.868 2924 3253 D DnsProxyListener: argv[7]=0
03-19 11:25:44.868 2924 3253 D DnsProxyListener: GetAddrInfoHandler for reports.crashlytics.com / [nullservice] / {104,104,104,917608,10132}
03-19 11:25:44.868 2924 3827 D DnsProxyListener: GetAddrInfoHandler, now for reports.crashlytics.com / (null) / {104,104,104,917608,10132}
03-19 11:25:44.873 3374 3374 V MediaRouter: Dispatching route change: UserRouteInfo{ name=null, description=null, status=null, category=RouteCategory{ name=Devices types=ROUTE_TYPE_USER groupable=false }, supportedTypes=ROUTE_TYPE_USER , presentationDisplay=null }
03-19 11:25:44.873 3374 3374 V MediaRouter: Dispatching route change: UserRouteInfo{ name=Nearby device, description=null, status=null, category=RouteCategory{ name=Devices types=ROUTE_TYPE_USER groupable=false }, supportedTypes=ROUTE_TYPE_USER , presentationDisplay=null }
03-19 11:25:44.873 3374 3374 V MediaRouter: Dispatching route change: UserRouteInfo{ name=Nearby device, description=Google Cast, status=null, category=RouteCategory{ name=Devices types=ROUTE_TYPE_USER groupable=false }, supportedTypes=ROUTE_TYPE_USER , presentationDisplay=null }
03-19 11:25:44.873 3374 3374 V MediaRouter: Adding route: UserRouteInfo{ name=Nearby device, description=Google Cast, status=null, category=RouteCategory{ name=Devices types=ROUTE_TYPE_USER groupable=false }, supportedTypes=ROUTE_TYPE_USER , presentationDisplay=null }
03-19 11:25:44.875 2924 3826 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:25:44.876 2924 3818 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:25:44.878 2924 3817 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:25:44.882 2924 3827 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:25:44.887 3374 3696 I zygote : Deoptimizing com.fasterxml.jackson.databind.JavaType com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.resolveMemberAndTypeAnnotations(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.introspect.AnnotatedMember, com.fasterxml.jackson.databind.JavaType) due to JIT inline cache
03-19 11:25:44.887 2924 3817 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:25:44.887 2924 3826 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:25:44.888 3374 3796 D libc : [NET] android_getaddrinfo_proxy-, success
03-19 11:25:44.888 3374 3803 D libc : [NET] android_getaddrinfo_proxy-, success
03-19 11:25:44.888 2924 3816 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:25:44.889 4478 32014 D libc : [NET] android_getaddrinfo_proxy-, success
03-19 11:25:44.890 2924 3818 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:25:44.890 3374 3805 D libc : [NET] android_getaddrinfo_proxy-, success
03-19 11:25:44.894 2924 3827 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:25:44.895 3374 3610 D libc : [NET] android_getaddrinfo_proxy-, success

A successful connect looks like this:

03-19 11:41:51.524 2924 3253 D DnsProxyListener: GetAddrInfoHandler for spclient.wg.spotify.com / [nullservice] / {104,104,104,917608,10132}
03-19 11:41:51.525 9041 9231 D libc : [NET] android_getaddrinfo_proxy get netid:0
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[0]=getaddrinfo
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[1]=spclient.wg.spotify.com
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[2]=^
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[3]=1024
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[4]=0
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[5]=1
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[6]=0
03-19 11:41:51.525 2924 3253 D DnsProxyListener: argv[7]=0
03-19 11:41:51.525 2924 3253 D DnsProxyListener: GetAddrInfoHandler for spclient.wg.spotify.com / [nullservice] / {104,104,104,917608,10132}
03-19 11:41:51.525 2924 9241 D DnsProxyListener: GetAddrInfoHandler, now for spclient.wg.spotify.com / (null) / {104,104,104,917608,10132}
03-19 11:41:51.526 2924 9241 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:41:51.526 2924 9241 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:41:51.526 9041 9231 D libc : [NET] android_getaddrinfo_proxy-, success
03-19 11:41:51.528 2924 9240 D DnsProxyListener: GetAddrInfoHandler, now for spclient.wg.spotify.com / (null) / {104,104,104,917608,10132}
03-19 11:41:51.529 2924 9240 D libc : [NET] _dns_getaddrinfo+, netid:104, mark:917608
03-19 11:41:51.529 2924 9240 D libc : [NET] _dns_getaddrinfo-, (NS_SUCCESS)
03-19 11:41:51.529 9041 9232 D libc : [NET] android_getaddrinfo_proxy-, success

Clearly the NS_success was missing before.

Went through the hosts file and found the following entries:

Went to the hosts file and found the following entries:

# 0.0.0.0 spclient.wg.spotify.com #[affects mobile app]
### SpotifyAds
0.0.0.0 gads.pubmatic.com
# 0.0.0.0 spclient.wg.spotify.com # GH-270

Funny enough the spotify parts are commented out so I wouldn't expect that to be a problem.

Hope this helps you a bit. I also have the full logcat should you want it.