I have a MIDI Solutions Event Processor and it works great to filter start messages from triggering my Mother 32 sequencer (I use a Beatstep Pro as my master). But, with those start messages filtered, the M32 also seems to ignore MIDI clock (stop messages still work) and does not sync tempo. Are MIDI start messages and MIDI clock one and the same to the Mother? The MSEP exclusively filters global start messages, no other filters are enabled.
FYI, I also have a Keystep sequencing my MS20 (slaved to the BSP via MIDI), it syncs perfectly behind the same Midi Solutions filter.