I'm finding that InDesign is breaking Command+Tab (app switching) in Big Sur, from 11.0 to 11.1, the current version.
Quitting InDesign brings it back, and simply booting InDesign breaks it. Leaving it open in the background once broken keeps Command+Tab broken until I quit InDesign.
I went through Keyboard Shortcuts as well as Apple's Shortcuts and found nothing conflicting.
All 2021 version, and all MacOS 11 versions.