Extreme Issue, units revert to level one

I have noticed that in HWW rounds specially, your units seem to randomly revert back to lvl 1. This is an extremely big issue and could cost you an entire game. I have suffered this for the first time as Germany, and I spent 2 hours waiting to get Germany, so...

My freinds have also experienced this, they say they have experienced it multiple times. Please look into this issue. Thank you

EDIT: I just logged onto another HWW, I was UK and was fighting France... every unit I had went to level one, you can guess how that ended