Ok so recently been receiving reports about users experiencing their outlook keeps flashes white pop-ups and remain disconnects, even their Internet is connected.
It seems this issue only occurs to users that never or frequently perform updates on their machine and office apps.
The solutions was to perform windows update and Office apps update to resolve this issue, if you have driver update, do perform that too.
If the issue still occurs, then you have to dig into the event logs to identify the issue. If time is limit, then you just proceed to uninstall and reinstall their office apps.
Sabrina Kay's Blog 