I moved houses few months ago and because my PC doesn’t have a built-in Wifi I had to use wireless USB Wifi Adapter connecting to Router (Huawei hg8245q2) with fibre connection in my living room (distance about 3 metres but 2 walls inbetween). For few months I've been using Asus USB-AC51 and it worked stable but the connection via 5GHz was pretty slow (2Mb/s max download, had to wait for basic Youtube videos to load, Stream at 1080p lagged etc.) so I decided to try different adapter. I bought TP-Link Archer T3U Plus and the speeds are much faster (Up to 18Mb/s) but when I try to download something bigger (mainly Torrents, Steam games) it goes fine for about a minute before the connection starts to slow down and stops completely in the matter of 20 seconds, download goes to 0 and I can’t access any websites.

All through 5Ghz connection, tried 2.4 and it's the same thing but slower. Most of the time I can wait few moments and connection comes back up and I can access websites again but it’s not usable if I’d like to leave the PC to download something big in one go.

I’ve done some basic troubleshooting: tried different USB ports, restarted the router and checked off power management options in the device manager for the Wifi Adapter. I connected the PC with the router via the Ethernet cable and it worked fine, downloaded 80gb in about an hour without problems.

It's Windows 10 Pro 20H2, ASRock H110M-HDV Motherboard

Any ideas what else I could check to solve this? Thanks in advance!