My reply to this existing thread did not get much attention, so i thought i could open a new thread for this problem.
I updated my OpenWrt installation to 19.07.6 and got my 2.4 Ghz wifi working again by uninstalling hostap_openssl and resetting the wifi encryption back from WPA3 to WPA2.
So to me it seems like the WPA3 encryption works just fine with the 5 Ghz radio of the router, but not with the 2.4 Ghz one.
For some reason the radio just stays inactive.
This is not so nice for me, because having access to WPA 3 encryption was the main reason why I installed OpenWrt in the first place.
Please test this in master, rather than the ~1.5 year old 19.07.x branch. Quite a few wireless chipsets can't do IEEE 802.11W (which is mandatory for WPA3) in hardware and fail in such a configuration - this has been mitigated (falling back to mac80211's software implementation; this comes at a performance penalty, but works) for quite s few of those (b43, rt2x00, early draft-n ath9k, …) last fall, the results of that have been merged to master, but not to openwrt-19.07.
Could you point me to the location where i can find the snapshot images for the Archer C2 V1? I guess those are based on the master right?
Or do i have to build OpenWrt on my own to try this out? In this case i would rather wait for the 20.x release