Hi,
Since the updates to cloud shell the editor capability hasn't been working properly. What you can do instead is use a different editor, for example nano . To start it, simply type nano
at the prompt.
Below is cheatsheet for Nano's shortcut keys:
https://www.nano-editor.org/dist/latest/cheatsheet.html
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP