How many times did you try to verify your number? If you try too many times, you're number will be temporarily blacklisted. Current recommendations (and what I had to do to resolve the issue) are to disable RCS, wait two weeks without ever attempting to turn on RCS, then try again. It's really stupid but it worked for me. Another thing I did was disable my VPN and such before turning on RCS again. It can take up to two days for your number to be verified. As long as you have the right permissions and such, it should work, just be patient.
This headache is what pushed me over the edge to commit to using signal, matrix, beeper with imessage, etc. Now about 95% of my communications are on something other than SMS or even RCS as it's just been annoying for me to deal with.