I have a few headless Pi 3 B+ and a few headless Pi W that all connect to my home WiFi with no problem. They all have the same image (2018-06-27-raspbian-stretch.img) and some times even the SD cards are swapped between 3B+ and W.
I recently upgraded my router to Asus DSL-AC52U.
Removed the old one, setup the same SSID and pass (maybe different channel?) with WPA2-Personal (with AES) and then booted all my Pi.
I now have a strange problem. All my Pi 3 B+ connect fine with no modification needed. None of my Pi W connect.
Any idea where to look first?