After reading the help file it looks like that when a character ages that they should get hp/mp as their age adjusted overages come in to play.

This is the way I presumed it worked.
Str/Wis maxed then hit mature, get 20 hp, 20 mana due to +1 to both Str and Wis.
Int/Wis maxed then hit middle aged, get 20 hp, 20 mana due to +1 to both Int and Wis.
Int/Wis maxed then hit old aged, get 30 hp, 30 mana due to +2 Wis and +1 Int.


What I noticed was no noticeable increase in hp or mana when hitting one of these mile markers when stats were trained to max.

I don't know if it was my gear lowering my max stat or something else.

Any chance this is broken or just my misunderstanding?

You have a misunderstanding - no idea where you're getting your numbers from.

But I did look through it and improve it, just to be safe.