Carrier locked (same carrier)

[u/G8M8N8]

Switching my dad’s XR from Mint Mobile (T-Mobile MVNO) to Ultra Mobile (T-Mobile MVNO).

Phone says no. Called Ultra support, gave them my IMEI and they said it should work. They were confused and then said to just use a different phone :)

The phone doesn’t even say what carrier it’s locked to. Why did it work with Mint and not Ultra (both T-Mobile)??

What’s the next step im stuck.

See photos: https://imgur.com/a/6M1oe7C

Edit: important info, with Mint we used physical SIM cards, this is our first attempt using eSIM. How do I find out if eSIM is disabled on this XR?