OnePlus Phones Provisioned Wrong
Recent OnePlus phones (e.g. 11, 12, 13, 15 and "r" models) support WiFi Calling on Verizon and modern MVNOs (Visible, US Mobile Warp, etc...)
If you activate one on Total Wireless, it won't get provisioned for that feature. Total Wireless please update your IMEI / TAC database to support WiFi Calling just like on Verizon and modern Verizon MVNOs!
This needs escalated to level 3 NOC / Core Provisioning support.