SMS Not working, Sending uses RCS

Anthony7a

Just put GOS on Pixel 7a, but can't receive SMS.
Carrier is Three in UK. 4G calling, 5G preferred network type both recommended.
Can make & receive calls.
Can send & receive RCS.

Added Google messages later, but same problem.
Rebooted, no change.

Any ideas

Anthony7a

I've swapped sims & it seems to work fine with an EE sim. So I guess it's a compatibility problem with the Three sim (which works fine in another phone).

Anthony7a

I've swapped the sims again and now the Three sim appears to work fine with SMS messages. Phone had done an OS update so maybe that fixed it.