Phantom iPhone behavior across two of five devices

Across my wife and and I and three daughters we have two 14 Pros, one 14 Pro Max, one 13 Pro, and one 13 Mini. Been set up with family sharing for years on a 2TB iCloud plan with no issues.

Two weeks ago my youngest daughter started having an issue on her 13 Pro where Messages would lock up/freeze. If you exited and went back in, it was a blank screen. No way to get it to recover other than restarting the phone. It would work for a few minutes then rinse and repeat. This problem also carried over to the phone app where you'd try to hang up on a call and it would would stay connected. After all the normal troubleshooting I completely reset the phone and restored from a backup. Worked fine for one week. Started doing it again yesterday.

As I was pondering what could be causing this my oldest daughter, who is on a school trip across the country, texts me that she's having the exact same problem with her one-month-old 14 Pro. With her being across the country and on hotel WiFi it's not easy to help her troubleshoot. But I've done the following:

• Force reboot (multiple times)
• "Reset All Settings"
• Sign out/Sign back into iCloud
• We have one family group text thread which I had them both delete
• Confirming that we have over 100GB of free space on iCloud and both their devices have over 100GB of free space locally

After all this it's still happening to both of them. I'd normally figure a Reset/Restore would do the trick but having done it with my youngest's phone two weeks ago it seems it will come back. In my head the next thing is a Reset and fresh install...but that's a painful process!

So weird it's happening to two of the five of us. Any other advice of something I may be missing would be appreciated!