AIs Suddenly Stop Moving/Attacking

Hello. I recently updated my engine version to 4.11 from 4.10. It was fine at first, no errors or such.

Today I opened the engine and all AIs in the map do not attack or move when they see my character. I have 40-50 AIs and all of them stays still.

I use “On See Pawn” to make them see me and attack me. It was fine for months until today. Is anyone familiar with the situation?

Okay I figured out the problem. Looks like navmesh is changed on itself, again. Interesting bug or something. I fixed it.