Note 20 Ultra can't enable Google Messages Chat Features (RCS)

I recently switched from a Pixel 4 XL on Google Fi to a Note 20 Ultra, and I'm unable to activate chat features in Google Messages.

I know AT&T has enabled it the feature on their network, as I have friends with S20 ultras on AT&T who have it.

Here is what I've tried so far:

Rebooted several times

Cleared data and force stopped Messages and Carrier Services

Made sure both are up to date

Phone is up to date

Tried Activity Launcher hack (no longer works)

Tried Messages Beta

APN settings appear to be correct

I'm not sure where to go from here. I read it can take 48 hrs after a port to get it working, but it's been 72 at this point, and there are texts and pictures I'm not getting because RCS won't enable.

If anyone has encountered a solution, it would be a great help. Thanks.