I am not sure 100% of this, but I report it anyway.
I think the "Me in Combat" or "Combat only" is calculated somehow wrong (or at least, partially wrong). Like, based on the two swords appearing over your level in the player frame.
I think it should be calculated with the lua function UnitAffectingCombat("player") (returning 1 if in combat, otherwise nil), because if you target a mob and you start autoattack at max range, you will see the combat swords appearing on your portrait. But that doesn't mean you are in combat, in fact you aren't until the mobs hit you or viceversa. I repeat, I am not sure if the function is correct, I may be wrong but I saw my class doing weird things when they werent supposed to be done, so I open this thread.
Thanks for reading