very nice!, which version of the 86u do you have (year/rev) ?
2018 HWVer 1.5
This is another data point for RT-AC86U users that (to me) strongly suggests a correlation between using JFFS / amtm / scripts and experiencing difficulty under 384.19. In this user's sig, they indicate "No add-ons just a gateway" and I believe that contributes to what has made their experience trouble-free.
While I dont use amtm, skynet, Cake-QOS etc or any entware dependent scripts or anything USB based, I do use the /jffs extensively for services-start, init-start, firewall-start, dnsmasq changes, vpn scripts, and a half a dozen other home brew scripts for maintaining iptables, dns, etc, and easier setup scripts which alter some settings quickly like wpa key timeouts etc for when I do upgrades/resets, and my static leases for dnsmasq are saved there.
Also currently working on a WAN IP change email script if anyone is interested, sends a couple emails to notify when/if your WAN IP has changed, my isp recently changed my IP (a rarity thankfully) and low and behold Im out in the wild and I couldnt connect to my vpn (I dont use ddns) and my website was down
this will now email me (near instantly) if the WAN IP changes...
Anyway.. Rmerlin explicitly stated caution was to be used with the AC86U with 384.19 if you use /jffs. I just simply heeded his advice... I went with backup only the individual necessary files from /jffs to usb (my scripts basically), full reset, update, format jffs, reboot, full reset, reconfigure manually (might have reset then formatted/reboot, cant remember) but only then did I copy my /jffs contents back from usb to /jffs and all was good.
45 days on and its in my opinion the best to date. I still have issues with persistent WLCEVENTD messages but I'm 100% confident this is just my old Android devices not playing nicely with newer devices on the network... dont ask me how or why as I gave up trying to figure it exactly but mixed AC and N devices (and older versions of Android) and combination of channel settings etc wreak havoc on generating those debugging messages.... maybe Ill contact ASUS and plead with them to remove them, but honestly theres so many other ways to deal with them.
Anyway, if you screenshot/note every changed setting on every settings page, updating/re-configure from scratch is literally 15-20mins... including a reformat of /jffs and reboot of the router, never really had an issue other than ones caused by my own boneheaded use of bad settings