[Google Pixel XL Questions & Answers] bestmvno.com:
No. And now I am truly confused as to what is happening. Let me take a few steps back and describe some of my troubles.

With my Verizon MVNO I initially had a problem where I either had LTE data and texts working but no ability to place phone calls, or I had data working at 3G only with phone calls also working. I assumed this to be some sort of APN issue. Of course I could not edit any or add any new APN's since I was locked out of the ability to do so being on an 8.1 AICP ROM. The MVNO thought I may have messed something up with the SIM to cause these troubles, as I initially tried to activate service by dialing *228. I did that to try and fix a somewhat unrelated issue that they could not immediately resolve for me (trying to get texts and data to work!). At some point they offered to send me a new SIM, which I turned down because at least in my experience, that's rarely, if ever, the real problem.

Eventually I came across that dialer code *#*#4636#*#* and played with several different settings and was able to resolve the problems on my own by doing so. After entering that code, a screen should pop up with several different options. Choosing "phone information" gives you the ability to see some specific information about your phone, how it is connecting to the network, and even more. In my case, I could see I either had "data network type" as LTE with "voice service" as not connected, or "data network type" as "EvDO-rev.A with "voice service as "connected." I don't believe the "preferred network type" was properly set here, but it may have been. It's been a few weeks since I had to do this. Either way, setting it to LTE/CDMA auto (prl) followed by clicking the 3 dot menu and then selecting the radio band menu and setting it to "automatic" seemed to fix the issues with a couple more steps involved. The other steps were to toggle the mobile radio power off and on, then going into the APN settings and doing a reset to default. Once done, the proper APN's were there and everything worked. Please note, the preferred network mode set using the dialer code, can be different than what is in your system settings. In fact, you have a lot more options to choose from by way of the dialer code, or at least I did. In both places though, you should try setting to LTE/CDMA auto and see if it helps with the other steps I just described. With the dialer code menu, you can also try to "trigger carrier provision." I did try that at some point, but it didn't seem to do anything for me.

Now here is where things got really interesting. The thing could be random and ROM specific or dumb luck or anything really. But somehow, while playing with the settings this evening for the purpose of this reply, I gained access to being able to totally edit all APN's and add new ones. It could be ROM related, but I was locked out of the settings before playing with a bunch of different settings combinations that I'm about to describe.

If the first set of steps didn't help you, you can try this or any different combination thereof.

Go to your system settings, and set your devices preferred network type to "Global." Use the dialer code mentioned above, and set the preferred network type to global as well (if it doesn't work, keep trying others), try setting radio band to "automatic" and then toggle mobile radio power off and on, go to your apn settings and do a reset to default, if that doesn't work you can try setting the radio band to "united states." Then toggle mobile radio power off and on again and reset apn settings to default. If that doesn't work keep changing the "preferred network type" to something else while also trying the two different radio band choices. I don't know how it happened exactly, but doing these things somehow gave me the ability to add and save new APN's that I didn't have just a couple of hours ago. Everything also works with the phone as it should, even with the network type set to Global in both places. I'm wondering if anyone else will have any luck trying these things out. If so, I plan to write a better and full guide on my site.