Any moving foward with this issue? Or maby it's already fixed with newer cores? Or atleast anyone got idea where the problem is?
Edit
Played with that issue a bit, deleted WTF and cache folders in client and when connected pet had different abilities automatic active, but well focus regen worked. After messing a little with pet spell bar (auto activating/deactivating) focus regen stoped again. Later I noticed some spells were active in pet spell book but not in pet bar. It seems there is something wrong not with focus regen but with pet active/inactive spells display and that causes frozen pet regenerated focus display. Something is wrong with mangos sending/receiving packets of activated pet spells