What is the expected behaviour for shared files if a user is disabled and encryption is used?

We have a lot of files shared by an ex employee. We have disabled his account but files he shared are now giving an error “DecryptionFailedException
Cannot decrypt this file, probably this is a shared file. Please ask the file owner to reshare the file with you.”

I wasn’t sure if this was a support issue or if it is expected behaviour? Is there any way to access these files?

ok, I’ve seen transfer ownership may be able to help here, but would still be good to know if that works with encryption or if there is a better option.