Hi Friends,
I need your help I am experiencing a strange problem with my sound card RME 9632,

I recently replaced the unbalanced cable of the card to balanced cable, it is important to me to point  that a few months ago I used the balanced cable  but because  strange noises that heard I replaced the balanced cable with unbalanced  and everything was normal, so i thought that the problem is because the XLR output cables, I bought a new cables, and connected again the balanced cable and now I get a new problem, the output level (left and right) is not equal. It is important to note that the card's ports connected to MON800 of Behringer that controls on the output level , when i connect the unbalanced connection I had no noise, when i connected the balanced cable i saw in the - level limiter of the device that there is differences between right and left.

And of course I checked the mixer of RME all seems good and  so I do not understand where the problem.
 
Ideas?

Thanks excellent day, Guy.