OMG it actually works! Just some finishing touches.

src/cthulhu/keybindings.py

@@ -520,7 +520,7 @@ class KeyBindings:
             if keyBinding.matches(keyboardEvent.hw_code, keyboardEvent.modifiers):
                 if event_str.lower() == 'v':
                     logger.info(f"MATCH found! keysym={keyBinding.keysymstring}, desc={keyBinding.handler.description}")
-                if keyBinding.modifier_mask == keyboardEvent.modifiers and \
+                if (keyboardEvent.modifiers & keyBinding.modifier_mask) == keyBinding.modifiers and \
                 keyBinding.click_count == clickCount:
                     matches.append(keyBinding)
                 # If there's no keysymstring, it's unbound and cannot be