Win version 10: Construction 20H2 19042.1266
Description of the problem: Attempting to download files larger than 1MB through various programs (Firefox, Steam, Windows Update, software installers) invariably fails the download if the download speeds significantly exceed 2MB / s (16Mbps). Steam reports “no internet connection”, Firefox reports “source file could not be read”, sometimes before starting the actual download (ie while selecting the file destination). Torrents run over the limit, and downloads below the limit also work normally.
Context of the problem: I recently upgraded from version 1909. I cannot switch back to this version because Windows incorrectly reports that I made the change more than 10 days ago. I also used the third-party “Windows Privacy Dashboard” software, but since rolled back all changes made by that program. As for the hypothetical maximum download speed, speedtest.net returns around 70 Mbps.
Attempts at solutions: Uninstalling all antivirus software and disabling Windows Firewall didn’t help. Switching to another wi-fi network did not help. I am currently out of range of the Ethernet cable, so I cannot verify if the problem is limited to wi-fi. Preventing the computer from turning off the Wi-Fi adapter to save power in Device Manager did not help. Performing all repairs offered by “Tweaking.com Windows Repair” in Safe Mode did not help. Notably, the safe mode itself made not exposing the problem, which only adds to my confusion.