I installed two AP AC AX One lite last week and have not had issues until today. Now the wireless network will not let random iPhones connect to the network and is randomly disassociating computers. Additionally, the connection speed went from 600 mbps download and upload to 25 as of today.
Welcome to the club!
Can you please check and make sure surrounding no other APs running using the same WIFI Channel for the AP AX ? Normally this happening when WIFI interference happen. You can check this by access AP —> Status —> Nearby Device.
If you found that the other strong WiFi SSID is using the same Wi-Fi channel, please try to change the AX using other channel and check again whether you still see the same issue.