MvQmXYxyA It is certainly dangerous to go without an antivirus in general. It's not particularly dangerous to do precisely one thing with the antivirus disabled when you know that one thing is not in itself a threat. That's why I suggested it, as a test.
If you don't want to try it, that's fine, but then the next suggestions start to get more time-consuming, for example a repair install of Windows. A simpler test would be to try a different network, for example using your phone (running off data, not your home wifi) as a mobile hotspot. I'm not at all confident it'll help given the errors you're seeing, but it takes less than a minute to try.