MPC Swing gone with sync'd to MIDI Clock

Ok - This is a weird one, but I just verified it over and over.

I am running JJ OS2XL Ver 3.83 on an MPC 1000 -

Running the MPC form it's internal clock:
If I make track with a 16th note swung pattern with a swing level of say 54% - all good

If I switch the MPC to be a Midi Clock Slave, receiving MIDI clock from another source
The Swing in the track is GONE. It plays straight, as if I had set the swing level to 50%

If I disable MIDI slave and just play the MPC from the internal clock --> The Swing is back.

Now, to make it extra strange, the issue is less pronounced with more intense swing settings. So if I make a track with a 16th note swing at say.... 65% then put the MPC in the MIDI Slave mode.. the swing is still there but less intense.

Try it!

MPC internal clock - swing at 54% - 16th note track... swing is all good.
MPC MIDI slave - swing at 54% - 16th note track.... swing is gone, track plays straight
MPC internal clock, swing at 65% - 16th note track ... swing all good
MPC MIDI Clock Slave - swing at 65% - 16th note track - Swing is still there though less intense

It's like the MPC swing less when sync'd to MIDI. It makes no sense, but it definitely behaves this way.

Thoughts?

Answering this for the sake of future folks -

So Syncing the MPC via Midi Beat Clock definitely messes up the swing timing. This is assuredly a bug somewhere.

The good news is that with JJ OS you can sync with MIDI Time Code (MTC) - MTC is more complicated than Beat clock and I had a challenge getting it to work.

In Logic Pro, under General synchronization settings I had to change the default and make sure that Bar position 1 1 1 1 1 Plays SMPTE 00:00:00:00.0 -

Then I made sure that Logic was sending Midi Machine Control (MMC) and that the MPC was set to receive MMC. This is configured ion the Synchronization --> Midi tab in Logic.

So MPC:
Sync In: 1 Slave
Mode: Midi Time Code
Receive MMC: On

Logic Pro:
File > Project Settings - Synchronization
General Tab: Bar Position 1 1 1 1 play at SMTPE 00:00:00.0
MIDI Tab: MTC and MMC boxes both checked for the MIDI output connected to the MPC

That worked for me anyway and swing was preserved.

this seems to be an issue on many pieces of hardware, not just jjos or mpc's...
i think it somehow requantizes when synced to external clock because the ppqn resolution is lower. midi clock sends 24ppqn while usually mpc's work with 96 or 960 ppqn depending on models.
midi time code on the other hand doesn't create issues because of the linear nature of the synchronization i think...
anyway i always prefer to have the mpc as the master clock generator.