Port over from At&t temp number wont go away

We ported over a phone and number from At&t back in March of 2023 . It's now almost August and if I send 10 different text to someone,  one or two of them will come from that temporary port in number . I'm also missing calls , dropping calls , have phone calls coming into my watch but the phone itself never rings . It's like the phone is bouncing back and forth between its actual number and the temporary port in number all day . I've called tmobile 3 times and stopped back in the store . I'm told the port in is completel, the phone shows the proper port in number in all the settings, they have reset diffrent settings and catches multiple times . Still does it . They told me to buy a tmobile phone instead of the At&t phone , we didn't need a new phone , but bought one anyway and it still does the same thing . We went back into the store and had the sim changed, still does the same thing . This particular line is a business line,  so this is problematic. What can be done to fix this other than take my 5 lines to a diffrent carrier? Please help 🙏