I'm so sorry that you're having trouble with your ROG phone and the aeroactive cooler.
Please try these troubleshooting steps:
Settings -> Advanced -> Mobile manager -> Cleanup -> Clear chache files. Long press Armoury Crate app icon -> App info -> Storage & cache -> Clear both. (Step 2 will reset all your settings in Armoury Crate.) Reboot your device and connect the AeroActive Cooler.
If it does not work, please contact a local ASUS service center.