So, probably spent an hour and finally figured out that my Asus router had 802.11ax / WiFi 6 mode “enabled” on the 2.4 Ghz. Had to turn that off for my Racho 3 , 12 zone to connect. Firmware was 640, not sure if the new one 645 works on Wifi 6.
Most IOT devices only work on the 2.4 band, including Rachio, The firmware update won’t change that as it’s hardware related and firmware can’t replace the the physical components of the device.