Been having the same issue here, for the last few days World of Warships and Total War Arena, The CV3 test and also Steam and MTGathering are not connecting either.
I think it's my router or firewall but don't know enough to diagnose it.
WoWs and MTG use different ports.
The ping plotter and tracert seem to get there fine, I think something is configured at my end to not allow the response?
I am using a TPLink router to which I am directly connected to XFinity in Seattle and Norton 360
Have rebooted and both the router and PC. Have not yet cleared DNS, has anyone else tried that?