@siens You could disable WebGUI HTTPS access for local management only. Thus the browser warning message shouldn't appear anymore.

@Diggery Have you went through the troubleshooting guide for VPN Client not working.

@BinnyK You can do either what you've described or to avoid the double NAT you can set AXE75 in AP mode (Case 1). Here's the difference between router mode and AP mode. Either case the connection...

@Eligijus92 Thats correct. RE315v1 as well as AX55 support Easymesh with an ethernet backhaul which will allow you to have a mesh network with the same SSID throughout your premisses - details. They...

@Eligijus92 If you use an ethernet cable you should put RE605X in AP mode - it doesn't support mesh ethernet backhaul. RE315v1 supports this feature - details.

Here's a guide on how to configure OpenVPN server on your router.