This sounds similar to a problem another user was having on the Reason forum that I frequent. Ultimately the issue was that his ISP was timing out and loosing connection with the download server. First thing I'd check is if you are on some hinky wireless connection in your house. My machine is connected to the router with a cable. No WIFI issues that way. Second thing to check would be your connection with your ISP.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740