IFWA repeatedly has SIM card error

In April 2022, I received an IFWA-40 from AT&T to replace the existing Wireless home phone device, since the original was 3G based. Plugged it in and waited a few minutes until signal was displayed. Gave it a day but was unable to make or receive calls using the cordless house phone. Kept getting calls cannot be made from this device. Incoming calls were denied as phone number unlisted. Called AT&T support and they stated the SIM had to be registered. Once they did that is worked great. 

About June/July, noticed I wasn't receiving calls on my home number, so I checked, and the IFWA-40 had an error showing SIM card issue. Called AT&T after several attempts to reseat, power off for hours, etc., but to no avail. They offered to ship a replacement SIM. Waited 60 days only to have the order canceled. Called them again, they overnighted a SIM. Inserted it and immediately got SIM card failure. Called them again and they recommended I take it to a local AT&T store.

I was travelling during that time, so I wasn't able to take it in until late September 2022. Local store rep stated that the card was no good and inserted and registered another one. Unit was working before I left the store...

Now, here we are less than 6 months later and guess what, SIM card issue again. Took it into the store this time and they popped in a new SIM, registered it and it never worked. They suggested I contact AT&T for a replacement IFWA-40 since it should not have 4 bad SIM cards in less than a year. 

Is there anyone who can help me with getting this replaced, since the online support keep wanting me to go to the store and the store folks tell me that they cannot replace it?