SonarQube QualityProfile rules discrepancy after the upgrade

We have migrated/upgraded Sonarqube from 8.9.10 to 10.4.1.
We are seeing rules discrepancy in our custom Quality profiles.
Old SonarQube V8.9 has 427(22 deprecated)
New SonarQube V10.4.1 has 394 (6 deprecated).
Language - Java
Why the discrepancy between the versions?
How to identify and add the missing 427-394= 33 rules?
Due to the above discrepancy, we are seeing discrepancy in the sonar reports.
Please advise. Thanks in advance.

Hey there.

Upgrading SonarQube means that some rules will be deprecated, others will be removed. You can check the changelog to see what changed specifically.