Hi,
Trying to sync an ever-changing virtual machine disk image in this way is probably going to create some unexpected/bad behavior. Are you actively using the pvm while it resides in the odrive pro synced folder and odrive is running?
What is possibly happening is that odrive is uploading the file, which is holding an open file descriptor on the pvm file, and preventing other applications from opening it properly. There could also be some strange application-level conflicts as parallels uses the pvm drive and odrive keeps seeing changes to it and tries to upload it.
I strongly recommend against having an active file of this type inside an odrive-monitored folder. It is fine for placing non-active archives/backups. Since odrive is a real-time, active sync engine that constantly monitors for changes it will keep seeing that file change and want to upload those changes. I imagine the upload, itself is going to take a long time, as well.