Just glad that I can stop chasing my tail on something that wasn't actually broken despite the built-in speedtest telling me it was. Now I can just focus down on getting the rest of the config dialed in.
Did you end up doing this? How is this setup working for you with the Merlin firmware? I'm running almost the same setup GT-AXE16000 + (2) ET12 nodes (mixed backhaul - one node wired one 6Ghz) + another AXE-16000 as a node so that I have good coverage for my 6GHz devices...finally got the config...
So glad to have found this thread as I've been chasing this for about a week off and on as I worked to get my new network setup stable and perform - the fact that the internal test is "lying to us" is maddening as I was pretty far down the rabbit hole trying to figure out why the best I could...