I just purchased this Archer T3U AC1300 Mini today and my download speed could only reach 1 to 15mbps while my upload speed could reach 150 mpbs.

My ISP plan is 150mpbs.

I tried re-installing the driver and doing the manual driver install didn't work.

I tried changing the WIFI channel also didn't work.

I'm using 5GHz since that's the only band that could reach 150mbps.

I'm only 2.5 meters away from my router without any obstacle between me and the router.

My smartphone and my laptop does not have this issue. Both are beside my desktop which is the one using the adapter.