FS#4238 - TL-WR841N v13 (SoC MT7628AN) wifi disappears after some usage

[openwrt-bot]

waynej:

TP-LINK TL-WR841N v13 (SoC is MediaTek MT7628AN)
with OpenWrt 21.02.1 r16325-88151b8303

Steps:
Connect computer A via Ethernet to the router (TL-WR841N)
Connect computer B via wifi (802.11n, WPA3) to the router
At B side connect to a shared folder in A
At B side copy a very large file (in my case >200GB) from A
wait for a while, and the copy would fail (less than 5% is copied in my case)
check the wifi in B, and found that there is no wifi - even the original SSID is gone, and other computers/devices also could not find that SSID either.

I tested 3 times, and reproduced 3 times.
Pity I didn't try this out in the original firmware (before I overwrote it with OpenWRT).

This might be the same problem reported in FS#3325.

[wenqingj]

Tested the newly released version 21.02.2 and the issue remains.
If you need more data, please advise me how to collect it. Thanks.