Unfortunately though this isn’t always the case, I can’t recall which device it was, but I definitely remember this being an issue on a midi-cv device I was using some years back, I ended up contacting the manufacturer and the firmware was updated, I think it may have been Flame Clockwork but not 100% sure, as it was at least 8/9 years ago.
I’d be inclined to check with NiftyCase to see if their module does support velocity zero as note off, just to rule it out.