Various issues with 5Ghz MT7610E

Using a TP-Link Archer C20 v4 with MT7610E I have installed kmod-mt76x0e which doesn't come by default and it detects the 5Ghz card. Configuring it it works to connect but a few minutes after booting the router the 5 Ghz SSID disappear and doesn't come back soon.

Sometimes the SSID may appear again but for short periods and then disappear again, very intermittently, therefore it is unusable.
Tested with Wifi Analyser and the SSID isn't even advertised.

I tried various different configurations as such:

• Changing the mode from AC to N
• Using 40 Mhz channel
• Changing the channel to use the groups 36-64, 100-140 and 149-165 but made no difference
• Changing the Transmit Power from Auto to different levels, but although it shows it on LuCI it doesn't seem to make any difference on the power signal.

If I am not wrong the Maximum Transmit Power for this card is 13dBm but it is possible to configure it with more and it shows up more under "iwinfo wlan1 info"

Also the Scan option doesn't seem to work either.

@nbd168 did you mentioned recently some work has been done on this driver asking us to test or am I mistaken and confused with other chip ? Is there anything else other than related here that is worth to give attention ?

Start by reproducing the MT7610E 5 GHz failure on the TP-Link Archer C20 v4 with the mt76x0e driver, checking whether the SSID disappears and whether scanning and transmit-power reporting remain affected. Done means the 5 GHz network stays advertised and usable after boot, scanning works, and transmit-power behavior is correct.