Let's start first by having you sign out (if you have single-player worlds you will lose them unless you move them to realms) Then uninstall/reinstall, sign back in and see if that fixes the issue. ^TK
Please visit our bug report site to see if the problem has already been reported: msft.it/6012bdbtg. You can upvote if the issue hasn't been resolved. If you think you've found a new bug, visit our help site here on how to submit a report! msft.it/6013bdbt9 ^TK
We have other ways to verify you as the owner of the account. If proven that you are the account owner we may be able to assist with the migration process. Please submit the ticket. ^TK
If the owner of the Realms client has updated properly the best option here may be to wait 24 hours. Not the best option, but sometimes it can take a bit for the update to push through fully on the first day. ^TK
Which version do you have? If it's the Minecraft: Java Edition did you make sure to migrate your account before trying to get the Bedrock decision? ^TK
This is for PC only, so if you have the Windows 10 Edition on PC then you would be able to get the Minecraft: Java Edition As well. You can learn more in the FAQ. ^TK
Since you have tried all of those steps I'm gonna send you up to the Realms Support Team: To keep your information secure, please complete our request form at msft.it/6016bjIK0 so we can quickly and safely assist with your question! ^TK
The best option here is to reach out to Microsoft/Xbox Support in that case so that we can take a closer look into this situation: msft.it/6013bjaeH or msft.it/6014bjaey. ^TK