Troubleshooting Network Registration Issues with AT&T and T-Mobile on Quectel EC25C-AFX Modem Chip

I managed to get my modem working, and I’m using three SIM cards from Verizon, AT&T, and T-Mobile. However, only the Verizon SIM connects successfully, while both the AT&T and T-Mobile SIM cards are experiencing network registration issues. I’ve already tried switching to the Quectel EC25C-AFX modem chip and set the correct APN settings for each carrier. I’ve also attempted to force LTE-only mode, but I’m still having issues with AT&T and T-Mobile. Any ideas on why this is happening or what else I can try?