Modem is plugged in LAN port or WAN port of TL-WDR3600? If WAN port, you should change router's IP to 192.168.2.1 to avoid IP conflict. If LAN port, your TP-LINK is working as an AP? DHCP is...

Any IP address obtained on your devices? MAC filter is disabled, right? Try to change security option to WEP or disable security. If still no luck, restore it to factory defaults and configure it...

You got a kit or just WPA4220? You need kit and ensure that they are communicating. Otherwise, you have to pair them. To login its web interface--http://192.168.1.1, you can change DHCP to static IP....

Your phone's connection is stable enough to be shared in such a way? MR3020 is in repeater mode? How about security type of your hotspot?

Your main router has no MAC filtering rules? You should double check Wi-Fi password of your main router. I don't think WA801 has been configured properly. Can you ping router's IP on web interface of...

It Is the latest for V1...I didn't encounter such a issue. Try to restore it to factory defaults. Reconfigure it and try again.