Well…likely the Bogner is not sending enough juice at that level. I don't know which pot on the amp works as loop level send. Often this is the Master, thus requiring some "bold"playing level to get the right input to the effect processor.
I'm assuming youare not playing that loud. But if you are…I'd check the Bogner manual or their support to know which level the FX loop works at.
-10 dB or 0/+4 dB?
If it's a "minus" value, then you need to use jacks, not XLRs, on the Eclipse.