Found this out in Destiny 2, which uses Shift-Escape to display exit menu. I have key 1 mapped as Escape (default: 1), key 11 (default: Caps Lock) mapped as Shift, key 20 left on default mapping (Space). Apparently, it doesn’t matter, since clearing any mappings does not change the effect. To verify, I have turned on reactive lighting, and pressing keys 11 and 20 together does indeed light up key 1 as well. HyperShift mappings are empty, there are no custom mappings in Windows. The effect is system-wide, as I have tried holding Ctrl on the main keyboard and pressing the same combination, and it invoked Task Manager, which uses Ctrl-Shift-Esc as a global shortcut.
A workaround I ended up with was clearing Esc mapping from key 01, which does not stop 11+20 from triggering 01, but at least now it doesn’t invoke any commands associated with Esc. Obviously, I am looking for a more permanent solution.
I would appreciate some insight on how to fix this, because it’s really frustrating to unintentionally close down game client by - let’s be real here - a very common key combination.