@Elishg 

Sounds like the Proton VPN is blocking you. 

  @ArcherC8 Not exactly. Any VPN that is connected from the AP exhibits the same behavior with any device assigned under the VPN. I's not unique to ProtonVPN, which is just using a wireguard setup. I've tested it with multiple VPNs and run in to the same issue. 

  @Elishg 

I suspect whatever VPN you run on the device attached to the router may have that issue although I have never tried it. Seems somewhat logical to me. 

  @ArcherC8 Perhaps I'm not explaining it very well, but there is no VPN connection running on the device connected to the router. The VPN connection is initiated and running on the Archer BE3600 itself. The Archer BE3600 features both a VPN client supporting (OpenVPN, WireGuard, PPTP, and IPSec etc.) that lets you initiate a connection on the router to another network and then you can map specific devices on your network to utilize that connection. The Archer BE3600 also has it's own VPN server that allows incoming VPN connections (OpenVPN, WireGuard, PPTP, and IPSec etc.) While connected to the VPN server on the Archer BE3600, every other LAN device is accessible except for any that are mapped to use the VPN. This happens regardless of the type of VPN connection established on the Archer BE3600.