Hello,
Thank you for contacting Rank Math and we are so sorry about the trouble this must have caused.
Please verify that you’re running the latest versions of the Rank Math plugins. According to the Rank Math changelog https://rankmath.com/changelog, the current versions are Rank Math PRO v3.0.44 and Rank Math Free v1.0.201.1.
To fix this, you can disconnect your account by navigating to WordPress Dashboard > Rank Math > Dashboard > Help and then simply disconnect the account by clicking on Disconnect Account.

Once you’ve disconnected your Rank Math account, you can connect it again in the same settings. In order to connect your correct account, click on Connect Now.

Once you click on Connect Now, please ensure that you’ve selected the correct account and then click on OK, Activate Now, as shown below.

Then head over to WordPress Dashboard → Rank Math → General Settings → Content AI and refresh the credits. Here’s a screenshot for reference:

Once done, please go back to using Content AI and it should work without any issues.
Hope that helps and please do not hesitate to let us know if you need my assistance with anything else.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.