Random ERR_Empty_Response message on different sites and browsers

I am having a weird issue that seem to start after upgrading to the latest firmware (SFOS 10.0.4 MR-4). Some sites, it seems to happen randomly, will not load and give the message ERR_Empty_Response. It seems to happen after trying to login to the site. Sometimes, if I clear out the cookies, it will work but then a few minutes later it will do it again. I have a site currently that does it all the time, but it works outside of the network (At Home). If I add an exception to the firewall for the for the domain, it will fix it sometimes. When it pops up, if I hit the information button next to the url, the browser says your connection isn't secure. Then another click on that says This site does not have a certificate. It's very strange and like I said it is random. It has happened on Dell.com. microsoft's live.com, DHL.com, and Regions.com to name a few. The main page seems to load but after any authentication, you get the err_empty_response. I thought it might be a browser issues, but it works when outside of the network. It also started happening right after the firmware upgrade which is why believe it is something on the XG. I contacted support and they were no help. Just the routine of trying things and they just closed my ticket out without resolution.