Revoke of Offline access tokens

Dear everyone,

I have a client that is requesting / working with offline tokens.
This client is not revoking the Offline tokens.

Therefore I set
→ Client Offline Session Max
to an appropriate time.

Unfortunately the tokens within the client → offline tokens are not been deleted after exceeding Client Offline Session Max.

Is there something else to do or am I wrong with my expectation?

Thanks in advance.