Sounds like the same problem I have. Midi input and output is on same channel. If you have midi output from SYNTH connected to midihub which is also connected to SYNTH input, midi loop messes up everything. Both input and output of uses same midi channel. Changing filter cutoff will send midi CC and it comes back to SYNTH through loop and messes up controls on SYNTH. Same happens to every control that has midi CC.
They should update SYNTH to have separate channel for each midi input and output. Also possibility to turn those off when needed. At the moment most of the time I have midi output cable disconnected in SYNTH to fix this, but I consider it as bug in software design.
I have a thread of this thing in here: