iPhone says 'Carrier update failed' and reports no service

I have an iPhone 7 with a weird issue. If I try to use a SIM, it will work for a little bit and then say 'Carrier update failed' and will show 'Searching' where the carrier is usually listed, followed shortly by 'No service', even with no SIM installed. Attempting to check anything related to cellular calling, texting, or data will make the phone crash and bootloop a couple of times. I've reset it, restored it via iTunes, etc. and nothing will work except waiting for it to fix itself and say 'No SIM', and then the issue happens again after I insert the SIM again.

While it says 'Searching' or 'No service', checking the cellular menu will show a blank screen followed shortly by a crash and short bootloop (as mentioned above).

I have resorted to using my SIM in a Pixel 2 my dad gave me and keeping my iPhone for iMessage, FaceTime, etc., however it is inconvenient to have to carry around two different phones, and seeing my texts appear on both phones when someone uses an iPhone to text me can get weird and annoying.

Has anyone experienced this issue before and is there a way to fix it?