Unable to reliably hide system touchbar

Desired behaviour: Use exclusively my static touchbar setup at all times.

I've recently been unable to reliably hide the system touchbar. I think this has coincided with upgrading to Big Sur 11.2. (MBP M1)
The 'show macOS control strip' box is unchecked, and I have tried resetting BTT. It will temporarily enable my touchbar but frequently reverts to app-specific setup.

Thanks in advance

BTT version: 3.553

This is driving me insane - anyone found a fix for it? I've tried deleting my presets and re-importing