I've recently switched to a new router and fiber connection (1 gbps) with both 2.4G and 5G gateways, and bought an Archer T4U V3 adapter to use with it.
I've followed all installation instruction properly, plugged it into a USB 3.0 port and connected it with the 5G gateway, however speed tests show an average speed of 7.5 Mbps in download and, oddly enough, 39.5 Mbps in upload. The wireless associated speed is shown to be 585.0 Mbps, and I've made some speed tests with an ethernet cable to check if the router connection was weak but the speed via cable is as it should be (8-900 Mbps give or take). I've tried different USB 3.0 ports but it changed nothing.
I've uninstalled and reinstalled the adapter several times already, but the speed remained low. The signal is always shown as good, and the distance between my router and PC is 10 metres (I'll install a signal repeater tomorrow).
During most tests I've noticed that the download speed always spikes at the beginning of the test (between 60 and 100 mbps, it's pretty random) then drops after a second or so and stays low.
I've tried making a test using my Galaxy A10 (which doesn't run on 5G) as a hotspot and the results were 51 Mbps in download and 24 Mbps in upload.
My PC runs on Win7.
Can somebody help me with this issue?