ASUS first tried this new UI on their ExpertWiFi series of products. It has been incorporated into the GT-BE19000Ai as the main interface. If you'd like to see what it's like this appears to be almost perfect replica of what I see on my EBG15. One...
I hope to get one when it's finally released but hoping for just one unit, meaning if anyone else local is also interested can split a multi pack and save a little over buying one unit individually...1-piece $699.992-piece $1299.99
Merlin firmware is separate from ASUSwrt and the designer Eric's goal is stability above all. It doesn't always work well with AiMesh.You may want to try Ethernet Backhaul Mode to see if that improves WiFi stability...
Routers work, but are more costly.ASUS also has a limited number of RePeaters that form AiMesh.... Plain Range Extenders from other manufacturers work as well.
Set it up as you've done with prior ASUS routers, submit a Feedback log. Describe the problem and time/date of failed connection attempt. In about 1 - 2 weeks try the connection again, even without a firmware being published/released.