Machinedrum (or any other ext. hardware) + Cubase syncing

Heya,

perhaps someone has an idea as to why they get out of sync as soon as I loop around a section? It’s stays in sync as long as I am not looping. Cubase is sending Midi Clock, the machinedrum is set to receive clock from external. This only happens when it restarts the loop, as long as it does not go back to the beginning everything stays “perfectly” in sync. I tried everything I could think off, incl. setting Timestamp…

I can’t be the only one having this problem?