Time Zone resets when phone turns off, resets or updates

I have had Samsungs since maybe the 9. I have always been able to set time zone not to change and it never has reset. (This was with the 9, 10, 20, 21, 22, 23 Ultra all with another provider.) I have the S23 now from T-mobile and every time the phone goes off, restarts or updates,  I have to go back in and manually turn off automatic time zone, etc. This has obviously made me late numerous times and even cost me money for missing appointments. T-mobile can't fix and Samsung says I can drive an hour away and bring it to the store because they cannot fix issue even with remote access. Please help. Is it possible it is a T-mobile issue amd they just don't recognize it as an issue? Iam happy with T-mobile but this is archaic and quite annoying. Is there a way to test it with the Sim in another phone without doing a complete switch?