@2Dr It depends on which VPN you are using? Clietn-LAN VPN is possible, but LAN-LAN IPsec and OpenVPN are not currently supported.

@Icehunter Do you want the switch which likes this: https://www.tp-link.com/en/business-networking/managed-switch/?filterby=5999%7C6000%7C6001

@Matt_B My EAP has no such issue, can you reproduce this issue stably?

@NewOmadaUser Are you using the ER605? The new firmware version of ER605 has not yet been adapted to controller 5.6.4, so you can't see it yet. However, the latest firmware version of ER7206 has...

@steve_togo V1, V2, V3 are hardware versions. I have asked tplink technical support before and they said that the hardware versions are different only in terms of the chips used, the firmware version...

@SaulCarvalho If you want two devices behind the ER605 to be able to access each other, you can set up an IPsec VPN. How to configure LAN-to-LAN IPsec VPN on TP-Link Router