GoW stalls during battles

Steam on Windows 10

What you were expecting to happen, and what actually happened:
I was expecting to finish the battle in any way. But GoW stalls and I can only close the exe.

How often does this happen? When did it begin happening?
It happens every now and then, but most times in Faction, Tower of Doom and Invasion.
It started last week during Invasion.

Steps to make it happen again
I have to play some battles Tower Of Doom, Faction or Invasion.
Sometimes it runs smooth, sometimes it stalls.
Normally, I can see it coming when GoW graphic gets slower.