New phone loses signal when switching towers

I’m trying this again since AT&T won’t talk to me like they said they would:

I got a new phone about 6 months ago. Since then sometimes when I leave home I lose service. If I notice I can either reboot the phone or switch to Airplane Mode then back and I am fine - until next time.
I have contacted Customer Service at least 30 times (really). They all are very nice and try to be helpful, but none of their "fixes" have worked. I finally asked to speak to Advance Technical Support and was told on more than one occasion that they would call me. I have been waiting for that call since November. I just called again (1/23/2023) and this time was told that there is no Advanced Technical Support for PrePaid