Momentum is not stacking properly during Public Game

I saw many topics about it in the www’s but without any solution.
While I am playing solo all is fine but while playing in the public game mode with more than 2 players Momentum is not stacking or stacking a little for example to 11 and then is not going up at all. (neither with SHIFT nor with a normal attack with primary skill.
This is happening from the very beginning with G.O.D set release.
thank you

It’s not the public groups causing this, it’s because you’re using Calamity.
Use a different weapon and Momentum stacks will work just fine.