this is a known problem which stems from the fact that via Generic Remote you normally work with 7bit MIDI messages (values 0-127). However, the panner has 201 values (-100…0…+100), therefore, some of the panner values have to be skipped when you are rotating a knob on a generic remote device. Unfortunately, the zero value is one of the skipped…
Although there is a workaround it’s not so easy to set it properly. Please, have a look at this post on the older forum:
Fortunately, your controller (BCF2000) is able to trasmit 14bit MIDI messages so you can set it accordingly and then tweak Cubase to accept these higher-resolution messages.