She struggles with the jumps even on simple courses: I see bars on the ground. This is becoming a bit depressing to me. I know she can do so much better!

Listening to people around me, I asked a French judge to remeasure my dog and, for him, there is no doubt: Kaïa should be in Intermediate (jumping 50cm) and not in large (jumping 60 cm). This could explain a lot!
I will ask to remeasure Kaïa in Belgium! Moving to Intermediate would be good anyway.