I ported my mobile number over from Contact Mobile to Mighty Mobile yesterday --- the port itself went smoothly, except my txt messages using RCS are still showing as being from the MM 029 number, rather than my ported 027 number. When I turn RCS off there is no issue, and it shows as the 027.

I contacted MM and they are claiming that they don't support RCS (see below), even though when I turn RCS on it does work (but has the wrong number). I also don't see how Mighty can not support it when another One NZ MVNO (Contact) does!

Does anyone know how I can try and fix this? I've tried the usual airplane mode, restart, sim off/on, checking APNs, turning RCS off in google messages, restarting, turning it back on, etc etc.