No access to internet or outlook after connecting to F5 Big IP edge client

Having an issue of getting to the bottom of this one it happens every couple of months and last for about 15 - 20 minutes. Users are unable to access websites like google, BBC etc. and outlook stops syncing. This is only happening to users who are connected to F5 in various location. Users are able to access the intranet.

Just wondering if anyone else has experienced this issue and what you did to resolve it. Currently running on version 11.6.0.

Thanks in advance.