first why you uninstall and install again? You can temporarily disable service for 5 min or you can manually stop service with passwd if you have one.
To answer your question,
I have something similar but not exactly as you.
I could not access to a web sites that use our public IP in white list. So when traffic is redirected to barracuda cloud it goes out with other IP. Then site that have our public IP in WL receive this request it simply do not allow access. I put this website in bypass field and it was working just fine.
Regarding slowness on internet speed,
I experienced this only while I was testing some features and set flex service to be fixed. Like this when some flex service have bad response it stay fix on it and my internet speed was bad. As soon as I changed setting so flex service can be changed automatically, my speed was back to normal.
Hope I help a lil bit.