When I use Cmd+K or the sidebar AI window, the functionality of copying and pasting text does not work. It also doesn’t work when selecting “Copy” from the right-click menu. The system clipboard contents are not being changed at all, it’s as if there’s a event handler listening to the keystrokes and then doing a JavaScript like event.preventDefault()
Found this related post - uninstalling Codiumate extension solves it.
Glad this was resolved! Let me know if any other features do not work for you.