UR-242 low signal

My name is Tamir.
I record my guitar, via stereo multi effect outputs, through lines input 3-4 on the UR242.
At first I had a great signal, but somehow the signal decreased.
By eliminates-changing cables, connecting others guitars and updataing the drivers- the problem does not come from my multi effect.
Any solutions?
Tamir Giladi

Someone please?