Initiative
When I end my turn for a character and multiple characters are going on the same initiative, the game sometimes skips the second character’s turn. Have also seen problems with joining a melee already in progress, such as restarting from the first creature’s initiative when a new combatant joins in.
Lighting
Lots of confusion on this. I have stood next to a goblin by a fire with a light spell on my weapon and had disadvantage because my target is in shadows. Darkvision seems to work sporadically, and Devil’s Sight seems to have problems as well.
Both of these really need to be fixed. But I think they will be.