Well, when the mode is Access Point, the RJ-45 interface is acting as WAN and you must visit the setup page via wireless. If you can already get to the internet via the cable, you just need to plug...

Well, I think you can send the logs to TP-link to solve this problem.

Well,maybe your 4G signal strength is already weak on that position, so it would be weaker when you get farther.

Well, maybe you can add multiple items of virtual servers to do this.

You mean get the Internet from the phone and then share by mr3020?You can just use the wifi hotspot of your phone.