Cannot catch Ctrl+Alt+F1 in WinForms MDI. Is it special?

My WinForms MDI application has several keyboard shortcuts set at ToolStripMeniItem items.

Among the following ones:

• Ctrl+Alt+F1


• Ctrl+Alt+F2


• Ctrl+Alt+F3

the first one is never triggering its menu item. Others work as expected.

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  Is it somewhere blocked/used? Is there some list of such blocked keyboard shortcuts?

  
  


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  Is there a way how to use it? (Preferably just via designer without adding special code?)