Hmm, well the fact it happens for you, even with a new project, does make me wonder if it is something on your end. I don't know for sure, it's hard to tell. It is strange it happened when build server went down, but the build server has crashed randomly over the years (this thread was originally about the build server crashing a year ago, but it sounds like it continued to work for you during 2022, despite crashing at random times).
Do you have another computer or laptop to test building with C3, just to rule out if it is your computer? Maybe you could use your phone on WiFi and do a build, then your phone on 4G and do a build if you have mobile data?
I know you said you have excellent internet, but could it be possible that you're experiencing packet loss? From your video, it looks like it keeps successfully reconnecting to the build server, then losing connection again. I found this website and I get 0% for "Total packet loss", could you try this website and click "start test" and see what results you get? packetlosstest.com
Do you use any antivirus software that might be reacting to receiving the download? If you use one, what do you use? Dumb thing to suggest, but it could be a rare coincidence that your antivirus updated and suddenly rejects incoming downloads in some cases.
It could very well be something related to the build server, but it is very surprising that you can't build a blank project. I'm guessing everyone else can build, since they're not posting here and this thread is at the top of the forums for the past days.
Just to be clear, I'm not certain it is a "you" issue, but I'm trying to think of possible issues that could be happening, since noone else so far is having the same issue.