I just switched from a 4 to 6a with a Spectrum sim, everything worked fine before, but I cant seem to get mobile data to function, sms and calling are fine, any ideas?

This happens to me sometimes.

From the owner profile:
Settings > Network & Internet > Internet > the gear to the right of your mobile carrier at the top > Mobile data (switch on)

Oddly enough as I was writing this and doing it on my phone to remember the menu names, mine was also off, but mobile data is working.

2 months later

Same issue. I can receive and send sms and voice, but data doesn't work. On Pixel 5. The apn is locked so I can't mess around with that. I loathe the idea of contacting spectrum support. Gonna keep searching for answers and hope someone reads this in the meantime. Will post whatever I come up with for a solution (if there is one)