Nexus 5 Cellular service not working

[iambumblehead]

Cellular service on my Nexus 5 is not working and I'm hoping for advice to solve.

I purchased this Nexus 5 "new" about a week ago and the first thing I did, after un-boxing it, was to install Ubports to the phone. I used the magic device tool to install the "legacy" ubuntu touch. The SIM card is one that I've used reliably with a Nexus 4 for the past three or four years.

Essentially, I know the SIM card is not faulty, but I didn't use the phone's Android OS and do not know if the phone is faulty or not.

Sometimes (infrequently) the phone connects with the Cellular service and can be briefly used, but it doesn't hold the connection and loses the cellular service after a short time. Somewhat frequently, the phone suddenly restarts and I've noticed that when this occurs, if the dark pull down "Network" panel is open, it shows "No SIM" in the Cellular area. Most of the time this area shows "Searching" or "Unknown".

The Cellular Settings panel usually shows "Carrier None" and the "APN" sub panel is usually empty.

I installed Ubports multiple times hoping the issue would go away but the issue is still there. I'm using T-Mobile in Los Angeles. Thank you for any help or advice you may give.

[iambumblehead]

@UniversalSuperBox recommended that I create a new APN with settings found on this page https://support.t-mobile.com/docs/DOC-28474

Unfortunately, I'm unable to add an APN. The phone won't save the APN settings. I click the check in the top right, but nothing happens. If I focus one of the inputs to bring up the keyboard, and hit "Next" multiple times, it just cycles through the inputs and doesn't "submit" the data.

There is nothing below the last input, which is for Password. If I exit and choose "Reset All APN settings, a dialog appears:

Reset APN Settings Are you sure that you want to Rest APN Settings? [Reset][Cancel]

I choose Reset, but the dialog stays there and nothing happens

[iambumblehead]

Below I've added logs which are obtained following instructions at the wiki. My phone just rebooted now and I made these log files before the phone instantly restarted again --I hope they provide information that will be useful. I googled this from the mesg below, but no result was returned, "rfm_init_wcdma_tx" :(

UTdmesg.txt UTlogcat.txt

[iambumblehead]

It appears this phone is defective :( @UniversalSuperBox and I installed LineageOS and a factory Android image and cellular service did not work with either of those. The LinageOS installation would frequently reboot (like Ubports does) but the factory Android install did reboot, but either way neither of them gives cellular service

[iambumblehead]

per request from @UniversalSuperBox here are the log files from the factory Android installation

ANdmesg.txt ANlogcat.txt

[Flohack74]

What a pity to hear tha you got a faulty device =(

[iambumblehead]

Thank you :). The overall nexus 5 ubports experience has been great. I'm ordering a new nexus 5 :)