Did you open the files on the OneDrive from File Explorer with MediaMonkey? In that case it would be File Explorer that keeps executing the open command.

Playback skipping when the files aren't yet available seems expected. MediaMonkey can't play something through that the system hasn't available fully.

I have my favorite songs on OneDrive. I just formatted my computer, so the files were not local. In order to get them "downloaded" onto my PC and imported into MM5 library, I highlighted them all, and right-clicked to "Play with MediaMonkey". A song would begin to play, and then end. I'm assuming because the full song hadn't been downloaded yet, and therefore wasn't available to play in it's entirety. It would then go on to the next song, and continue playing small segments of songs.
The problem was when I pressed the stop or pause button, the media player just kept playing the next song that started to download.
Then, tired of this issue, I closed MM5. WOW! Badness!
What happened after I closed MM5, was that a copy of MM5 began opening for every song that was still being downloaded from OneDrive.
I reset my PC to abort this issue. When I loaded up MM5 again, all the settings had been reset to default.