I noticed an issue recently on several windows computers using a wired connection on my home network (120Mbps up/down) and when doing downloads/updates in the Microsoft Store (games from Game pass, app updates, etc) for example I want to get "Fallout 76" which is a 70GB download and its currently going at about 100Kbps and has been for several hours.  Even a recent Minecraft "update" which was 225MB took over an hour. I can use traditional speed test from these machines and it shows the full speed of the connection (120/120).  However, much like speed tests, using Steam for game downloads goes much faster (80/100Mbps typical).  

"Oh its just slowness from microsoft!" you will probably want to reply.  Now heres where it gets weird.  If i take that machine and plug it directly to my ATT gateway (bypassing the deco router) the speed is IMMEDIATELY faster.  Like full throttle, 100Mbps or more.  50GB downloads that sat for a day and hardly budged, will be done in an hour.  Its definitely something in the Deco router slowing these downloads substantially.  What could it be?  And why is there no option in Deco to TURN OFF QOS. I dont want it and if i knew it was so destructive to my network I definitely would have passed and purchased a different router.