I'm in the process of trying to determine if my RT-AX86U has developed hardware issues or not, or if it's certain devices on my network. Lately even after doing a clean configuration of the latest firmware, my Amazon speakers randomly report no internet. However, it only lasts about a second, or 2 each time. I consider this odd, since they've never had this issue before and I've been using fixed channels. 6 for 2.4ghz and 36 for 5ghz, the amazon speakers are on the 2.4Ghz network and they seem to be the only devices showing any kind of network drops. So, it's possible they're having an issue and it's not the router. However to further confirm this, I've put my TPlink router back in place it's different hardware, and software on the router end. If this happens like this, it's most likely an amazon issue, if not it was probably something wrong with the Asus. Considering this is a recent issue within the last month, and it doesn't happen regularly, and the fact my amazon speakers have had a few firmware updates, it's completely likely it's a client issue but changing routers will help narrow that down to be sure.
Anyway just thought I would post since my setup has been for the most part stable with the exception of this recent behavior. If things go OK with the TP-Link will either do a factory reset on the Asus, or just wait for the next firmware for it, and then do a factory reset and start fresh to see if the problems go away.