I downloaded Audacity 18.104.22.168 and tried. The same behavior happens.
The same behavior happens with every preset. I chose Celine’s recent preset since that is just an LFO through the bus to the output and so the problem is really clear with it and you could eliminate any mistake on my part patching up a preset. Also, you can easily reproduce my test setup WRT the Percussa.
I am currently on the road, so I only have a limited testing environment. However, If I go out of the Percussa analog outputs and into an iRig Duo and then use the USB audio input from the iRig, the problem does not occur.
The Percussa is set to 48K. The AudioMidi Setup app in the Mac recognizes it as a 48k device and both Audacity and Protools recognize the Percussa 2x2 interface at 48k.
It sounds to me like either a buffer overrun or a mismatch in sampling rates at either end of the MIDI interface. I have the Percussa set as the clock source. I haven’t tested with the Mac as the clock source.
I am running the most recent OS X 10.13.6 on a 2.9 GHz 2018 15 inch MacBook Pro.
Let me know how you want me to send the video.