Wireguard VPN to device in network (via internet) does not work?

I am an absolute Wireguard-Greenhorn, sorry for that! We have this setup Some local network with at least 1 device (Raspberry Pi based data logger ) and 1 router for internet access (connected via ethernet). Some PC wants to connect to the data logger, at least for installation / configuration, via internet, but in a secure way. No other party should be able to do this. So we've thought, we would need a VPN and installed two Wireguard VPNs on the router. One for the data logger, one for the outside world . Both clients (data logger, PC) use the Wireguard configuration for starting their own Wi

Question by BairDev on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.