[Xiaomi Mi 5s ROMs, Kernels, Recoveries, & Other De] yellowcup:
I'm able to reproduce this. Same build and firmware. Logcat: pastebin.com/raw/DEUEY3Nn. Some relevant bits:

06-26 12:21:53.881 493 18577 I WifiHAL : event received NL80211_CMD_VENDOR, vendor_id = 0x1374, subcmd = 0x7f
06-26 12:21:54.273 493 18577 I WifiHAL : event received NL80211_CMD_VENDOR, vendor_id = 0x1374, subcmd = 0x7f
06-26 12:21:54.279 2134 2134 E cnss-daemon: Invalid len 192 for 106
06-26 12:21:54.279 2134 2134 E cnss-daemon: wlan_service_update_tcp_rx_params input message of insufficient length 4
06-26 12:21:54.280 18580 18580 I wpa_supplicant: wlan0: CTRL-EVENT-DISCONNECTED bssid=e6:cb:ac:88:59:af reason=0
06-26 12:21:54.280 18580 18580 E wpa_supplicant: nl80211: Failed to open /proc/sys/net/ipv4/conf/wlan0/drop_unicast_in_l2_multicast: No such file or directory
06-26 12:21:54.281 18580 18580 E wpa_supplicant: nl80211: Failed to set IPv4 unicast in multicast filter
06-26 12:21:54.292 2197 2708 E WifiVendorHal: stopRssiMonitoring(l.2156) failed {.code = ERROR_NOT_AVAILABLE, .description = }
06-26 12:21:54.292 2197 2708 W WifiConfigManager: Looking up network with invalid networkId -1
06-26 12:21:54.294 2197 2730 D ConnectivityService: NetworkAgentInfo [WIFI () - 145] EVENT_NETWORK_INFO_CHANGED, going from CONNECTED to DISCONNECTED
06-26 12:21:54.294 2197 2730 D ConnectivityService: NetworkAgentInfo [WIFI () - 145] got DISCONNECTED, was satisfying 12
06-26 12:21:54.295 2197 2719 D DhcpClient: doQuit
06-26 12:21:54.297 2197 19845 D DhcpClient: onQuitting
06-26 12:21:54.304 3048 3203 I QCNEJ/CndHalConnector: -> SND notifyRatConnectionStatusChanged(rat = 1, DISCONNECTED)
06-26 12:21:54.304 2197 19848 D DhcpClient: Receive thread stopped
06-26 12:21:54.308 3048 3203 I QCNEJ/CndHalConnector: -> SND notifyRatConnectionStatusChanged(rat = 1, DISCONNECTED)
06-26 12:21:54.313 2197 2719 D ApfFilter: (wlan0): shutting down
06-26 12:21:54.314 2197 10681 I WifiService: getWifiEnabledState uid=10055
06-26 12:21:54.314 2120 2176 D CommandListener: Setting iface cfg
06-26 12:21:54.316 2120 2168 I Netd : Destroyed 11 sockets on 10.5.2.185 in 0.6 ms
06-26 12:21:54.318 3048 3199 W QCNEJ : |CORE| network lost: 145
06-26 12:21:54.320 3048 3199 W QCNEJ : |CORE| onLost: unbind the process to WIFI
06-26 12:21:54.329 2197 2759 I GnssLocationProvider: WakeLock acquired by sendMessage(UPDATE_NETWORK_STATE, 0, 145)
06-26 12:21:54.336 2197 11824 I WifiService: getWifiEnabledState uid=10055
06-26 12:21:54.342 2197 2708 D WifiStateMachine: WifiStateMachine: Leaving Connected state
06-26 12:21:54.361 2197 2261 E GnssLocationProvider: updateNetworkAvailability failed
06-26 12:21:54.362 2197 2261 I GnssLocationProvider: WakeLock released by handleMessage(UPDATE_NETWORK_STATE, 0, 145)
06-26 12:21:54.364 2197 2705 D RecurrenceRule: Resolving using anchor 2018-06-26T12:21:54.364+01:00[Europe/London]
06-26 12:21:54.366 2197 2705 D RecurrenceRule: Resolving using anchor 2018-06-26T12:21:54.366+01:00[Europe/London]
06-26 12:21:54.368 2197 2705 D RecurrenceRule: Cycle 17 from 2018-06-25T00:00+01:00[Europe/London] to 2018-07-25T00:00+01:00[Europe/London]
06-26 12:21:54.368 2197 2705 D NetworkStats: Resolving plan for NetworkTemplate: matchRule=MOBILE_ALL, subscriberId=234106..., matchSubscriberIds=[234106...]
06-26 12:21:54.375 2197 2705 D NetworkStats: Found active matching subId 2
06-26 12:21:54.385 2197 2705 D NetworkStats: Resolved to plan null