Aspect of Might is only giving 15% damage reduction, not 20% as stated.
If you already have damage reduction there’s diminishing returns the more you stack.
There’s no diminishing returns with Tyrael’s might nor Doom Bringer. Aspect of Might isn’t working as stated.
Who told you that? Any stack of a particular DR stack has diminishing returns.
As this stat increases, additional bonuses become less effective.
Directly from the in-game tooltip for All Damage Reduction.
As far as the aspect not working, everything works fine on my end. The aspect says 20%. The buff icon says 20%.
If you already have All Damage Reduction from other things (which it sounds like you do considering you mentioned tyraels and doombringer), then the AoM will be less effective.
Ok this post is for the devs to work on the bug and not in game players.