Collaborative Editing mode not activating

Collaborative Editing mode not activating

I am evaluating Zoho tools to see whether they would fit my team's needs. If so, we are likely to purchase Business level service, and to recommend Zoho to other groups in our company.

I have a document that I have shared with other individuals with read/write permission. I want to use collaborative editing mode to work on it with them simultaneously.

When I try to edit my document when someone else is already editing it, I get a message that: 'user' is currently editing this document. Entering shared edit mode ...

This message stays on the screen for at least 10 minutes (haven't had the patience to wait longer). It's unclear to me whether I am supposed to close it, or wait for it to go away. If I close it, my document is not opened. If I try to open the document again, it opens in normal mode, and versions saved by me and my collaborator clobber each other.

Is there some magic trick to collaborative editing mode that I am missing?