It is rare, but it happens, that you want to "tab" your code in VSCode. But if you ctrl+M by mistake (and mistakes are so often on the keyboard), the Ctrl+M toggles the tab key to "switch focus between windows". And I did not even notice. It felt like an intermittent bug, until I looked into shortcut keys, and looked for "tab".
The photo is reminiscent, of the once available flights!