@cplusplus1 If R600VPN be a L2TP VPN client,it should need to set remote subnet. The router will create a routing according to the remote subnet. But I did not see this routing in your screenshot....

@Andrew_Vint It should be a Gigabit Port. I think you can keep auto mode. And the peer device uses auto mode as well. If can not get 1000M speed, try to check your cable, it should be cat5e or higher.

@arhancock Please note that TL-R470T+ is a NAT router not a traditional router. If you need data transfer between LAN and WAN, you need to think about the NAT. You still need to think about subnet...

@TITP When ER6020 fails, could you access its web-gui? If yes, you can check its system log and WAN status. If cannot access its web-gui, try to ping the router's LAN IP for checking if the router...

@Ian2020 I lost the beta firmware as well... Maybe you can contact TP-Link support to get the beta FW.

@CsGabor You can refer to the FAQ. It's similar to your scenario. https://www.tp-link.com/en/support/faq/887/