Select all text in issue edit window

I want to hit control-a/copy in an issue edit window to select all text and put it in the clipboard.
The control-a doesn’t work, i.e. it doesn’t select anything.

Other keys in GitLab keyboard shortcuts | GitLab
do work.

I’m running linux ubuntu 20.04 running chrome.

so does control-a select the whole window on mac/windows?

There was a linux note about os or browser overriding some keyboard shortcuts.

Anybody know which it might be?
Rather than disable os/browser us, is there way to add a keyboard shortcut on GitLab? i.e. I pick an unused key and assign it to select all.

Any thoughts appreciated.