Dear Xara...
You do not have a Key shortcut for the Screen Capture tool.
If I use my mouse and pick Utilities > Screen Capture I get the top image with Key shortcut Ctrl+Q.
I also get this with Insert > Image > Screen Capture.
Bug - If I instead use either Hotkey selection of Alt-U-S or Alt-I-I-S, I get the bottom image with Key shortcut S.
Trying this fails.
Attachment 126131
Acorn