IC2 armor gets destroyed when you are morphed, sometimes takes a few hits.

Fall damage and Rain damage both also take durability from all armor when morphed

Are there any errors in the logs?

Nothing that I can see, checked the debug log too and there's nothing there. Fall damage is the best way to see the issue, with nano armor.

The helmet is usually getting damaged when you're morphed in undead morph and you stand on the sunlight. That might be your issue (it's a feature, basically 😂). Do you have any other mods installed?

Any update?

From what I saw it was IC2 armor that took durability instead of taking EU from the armor.