Two things I've noticed lately that I wanted to mention:
1. When entering PvP zones like Cyrodill or Battlegrounds, summoning Sorcerer pets results in them having less than their max Health and not regenerating to full.
2. When near members of a group (like at the start of a BG), the Twilight will not heal the Volatile Familiar, even though the Familiar is below max Health and all members of the group are at full health.
@ZOS_GinaBruno