Tadvmenu's shortcuts do not work

Windows 10, Delphi 10.1, last version TMS pack
Take AdvToolbar demo, change shortcut for "open" in Tadvmainmenu to ctl+Alt+O
Compile and run. shortcut does not work
Tadvdockpanel version 6.5.2.7

The shortcuts with combination ctrl + alt are indeed problematic. We have unfortunately not yet found a reason or workaround why in a descending component this particular shortcut key combination is not being received at control level.

Is there a way to "forward" these keystrokes?

You could try at form level to handle the OnKeyDown event with Form.Keypreview = true.

To which control (Tadvdockpanel, Tadvtoolbar, Tadvmainmenu) should I forward and what kind of message?

You can simply create an Action (TAction) and assign it a keyboard shortcut.

This would normally be the menu item associated with the shortcut