Random reboots - 2 MediaTek MT7620A devices - 21.02.1

Me too with random reboots with dir-860l (MT7621) and 21.02.1
I don't use wireless and the only installed and active software is SQM.

Has anyone understood the cause?

I tested WLR-4100 v1 002 (MT7620A + QCA 8337) with the master branch for few days: no reboot.
I did not have chance to test with 21.02 because the QCA 8337 connection is broken because of missing

if someone with the problem knows how to use UART serial pins, monitoring serial might show the problem, that involves opening the case of the router, maybe soldering if pins are not present....

other than that it seems to be a memory problem....

my PR that was linked is unrelated to this im sure

Good news folks! Updated TP-link Archer C2 v1 to 21.02.3 two days ago and didn't find any issue so far!

Poor power supply, low quality or omitted capacitors... Anything

Suddenly also with 21.02.3 random reboots. Cudy WR2100 (mt7621)

Sitecom WLR-4100 v1 002 (MT7620A + QCA 8337) is working fine with 21.02.3 for 25 days.