I have noticed that when i dismount (from any mount) with my dardevil, i always have 2 endurance bar filled even if i previously mount with maximum endurance (all 3 bar full). If i mount with less than 2 endurance bar, it will only regenerate up to 2 bar.I started noticing that around a week ago( but it's has probably started way before that) and i'm getting this everywhere in the game.