[TYPO3-english] Logging Out

[Fiona Bewley]

Hello Typo3-ers

I need your help with what seems like a simple issue.

My Mac latest OS Version continuously logs me out of typo3 backend when I am working on the website I am currently editing. 

All three browers: Safari, Firefox and Chrome have the same issue. After a few mintues, sometimes even 30 seconds when i am mid click, or writing some text or looking to add a picture from the Data List, I am logged out.

An older PC with the same website and log in does not however suffer from this problem. My Boss' Laptop (windows) doesn't either. 
I live in Germany and regardless of which internet network I am connected to, I am consistently logged out and also if I turn a VPN on. The Web developers with whom we are working have no clue how to help as they have never seen this problem before. 

When I was  in China and therefore travelling with my Mac, it didn't happen there and I could stay in backend for longer periods of time. 
All these factors tell me that there is some internet configuration which I am not able to address (being pretty illiterate when it comes to settings etc). 
Could anyone tell me which settings I would need to alter to solve this issue? Does it have something to do with Cookies? Or the browser?

Any help would be much appreciated!

Thank you