I am using a TP Link AC750 WiFi Range Extender and it works really well except for one thing: It cuts out every now and then. We had this problem with our old extender but it basically just cuts out every 30 minutes and takes 20 seconds for the computer to connect again. The LEDs say it's on though, and it has a good connection to the main router. Is it a problem with the main router or the extenders?