Multiple windows closes when clicking the "x" (close) button without alerts

Hi everyone,

I hope someone can help me with a problem I have working with office 365 files.

When I'm using office 365 applications, I usually open multiple files to work back and forth between them.

When I click the "x" button on the top right corner to close one of them, sometimes the whole application closes, including the ones that I did not want to close, and worst of all this happens without any alerts to save...

Has anyone run into this problem?

I think this started happening after the recent update in office 365...

Thank you.