In Google Docs on Chrome, the Cmd+Shift+X is supposed to be strikethrough formatting. However, what actually happens is that the mouse cursor changes to a thin cross and it is possible to select a part of the page as a picture. I didn’t find this shortcut listed neither in Mac nor Chrome shortcuts. This works as expected on Firefox so it is definitely a Chrome thing.

Do you know where it comes from and how to disable it?

Macbook Pro 16″, Monterey