I seem to be having (possibly) the same issue with 19.7.3 (my first install), where every 24-48 hours some devices aren't able to connect via wifi. I get errors like "Authentication error" on Android, or just repeatedly asking for the password on my PinePhone with UBtouch. Restarting the router and affected devices fixes the issue temporarily. Strangely, some devices like our Xbox One and Chromebook seem unaffected.
I'm running on a C7 v5 with the following specs:
Model: TP-Link Archer C7 v5
Architecture: Qualcomm Atheros QCA956X ver 1 rev 0
Firmware Version: OpenWrt 19.07.3 r11063-85e04e9f46 / LuCI openwrt-19.07 branch git-20.221.53167-304ad04
Kernel Version: 4.14.180
I skimmed a lot of this thread, but not all of it, so are there any general suggestions people are trying? KRACK seems to be already off by default already. Is there an ath10k package I should be installing? I didn't see one for QCA956X... i'm also planning to check if my ISP supplied modem is also using the same internal IP a la this post.