WIFI frequently down (19.07.3, TP-Link Archer C2600)

[frollic]

07.3 works without any issues for me - 235 days uptime, and counting.

the other two are stable on 07.6, after scaling_governor was set to performance.
84 and 54 days uptime.

Unexplained hangs freezes and reboots with Archer c2600

I've been running a TP-Link C2600 for over two years now. Been through all OpenWRT versions from 17.01 to 19.07. The issue is the unit freezes and hangs quite often. Most of the time it reboots automatically. Sometimes the lights stop blinking, and I have to yank out the power cord to recover it. I can't find anything in the system logs or dmesg. Has anyone else been experiencing similar symptoms? I suspect I should use the Widlarizer to fix it.