You'd only have timing issues when using the auto trigger, I assume there is a hole in the top of the body which, when the bolt is out you can stick an Allen key through to adjust the lug on the hammer. If the marker is firing before the pump is forward far enough then turning that in a bit should make it fire later in the pump cycle.
Canon - yep there is - when using the auto trigger, seems fine. Still think I was short-pumping it.
When I get my phone back from repair, i'll record a video of it
Look down the feed neck and slowly pull the pump back, when you hear a click to indicate its cocked check the bolt has cleared the breach. If it has you just need to pump further or pull the trigger slightly later, the rotor is probably forcing the paint past the bolt before its all the way back which is why it will work with the rotor but not a normal one.