Loss of Playback Engine Mid-Session

[DEliker]

Started running into this a week ago.

ProTools is randomly freezing and then failing to see my Clarett 2 interface.
Upon rebooting the app, the input is missing. Only the Aggregate is seen as a playback engine choice.

Yet all other 3rd party apps and internet work, and the System still sees my Clarett and other devices.

Trashing the Preferences, full shut-down and restarting the system, reinstalling PT, doesn't resolve the problem.

Yet the next day or a couple hours later, I'll fire up the system and everything works again. Completely inexplicable. Happened twice today right in the middle of simply playing back a single voice track. The app freezes, then restarts, and the device is lost.

I've gotten this message when first trying to access the Playback Engine:
Could not complete the Playback Engine command because Assertion in "/Users/autobld/gitlabci/PT/release/2021/r2/ProTools/DFW/Views/UMenu.MacOS.mm", line 1843.

Anyone thoughts? It's really getting in the way.
If it was a device issue, the system shouldn't see it and other apps shouldn't work.
If it was a simple crash, the device should be seen upon reboot.
But the app is refusing to see anything else.

Grateful for any help.
Thanks.


Specs:
2018 MacBook Pro
macOS Big Sur 11.4
Clarett 2 Pre USB
ProTools standard 2021.6