Asserting bumps values

I've a show on one master and front on another master.
The show master is at full, and also contains some front lights.
Between songs it's just some blue lights at low recorderd on the show master.
If I raise the front master where front ligths are recorded at full, it works until I release the front master, when it's asserting to the show master it flashes up and then down directly even with assert times on masters at 0.

What am I doing wrong?
Christian