Multiple concurrent Edits

[Vidhya Venkateswaran]

My team were attempting to edit a document and we are aware of the Cancel, continue, overwrite options; however, when one person tried to save the document, while another was still editing, the override option was the only one visible. 

Wondering if this is a known function or a specific scenario that we encountered. 

On clicking Overwrite, however, all my colleagues changes were lost. 

Thankfully, he also had the doc open, so could re-do the changes.

Any suggestions to overcome the issue is welcome