Omen of Amelioration‌ - Not working

It seems random, but i died two times in a roll without triggering the Omen of Amelioration (the one which prevents 75% exp loss when dead) .

Scenario is a T17 Citadal, with shaper-touched mod.
The first time i died, the omen triggered correctly. But the second and third time it did not trigger at all, despite i have another one in my inventory.

Each player can only consume one Omen in each combat area.

If omens were not consumed in the same map this would be why.

I died (yes my first death) in a Forge of the Phoenix map with an Omen of Amelioration in my inventory and it did not trigger. I went back into the map, died again and it did not trigger again.