It doesn't matter how you call it.
But it does matter what it is.
You are still fighting with the issue - find your fix. I shared with you my experience.
I'm trying to. But you just won't shut up about your proclaimed solution, without addressing the answers you get, namely that
the issues persist across 3 AC86U's, but varies varies with different firmware revisions. How is this logical that all three are affected by hardware failure that "magically" improves with newer firmware?
Stop derailing my conversations when I'm trying to actually seek out a solution unless you can bring anything substantial to the table, such as a way to diagnose the issue.
What I found inside this specific AC86U model is described
here, with short list of common issues and symptoms. Based on my findings, my recommendation is to replace it.
Not only is that anecdotal evidence; btw you state yourself that they (a) are a selection of refurbished routers that (b) customers are bringing to your repair shop. Do you not see what is going on here?
What you are going to do with your router is your decision. Complaining in every thread how bad Asus is definitely not going to fix it for you.
Well, the issues have improved since I started complaining about it, so although we don't have the data to establish a direct correlation, we do have data that your statement that it is
definitely is not going to improve it is definitely false.