I think there should be more details regarding your stamina regeneration in the stats, such as base regen, armour penalty, encumberance penalty etc.
These changes to stam regen are fairly new. I only knew about it cause I read up on patch notes often. Regardless of that, there should be some mention of these mechanics in-game. The stats menu would be the perfect place for it.
In addition to that, there should be a general loading screen tip telling us that we find out how our amour, attributes and encumberance levels are affecting us from the stats menu as well.