I am testing for now with a mango router working as ovpn server, limevpn and protonvpn. I will test with more services later. No issue with wireguard, but openvpn is giving issues. I created another thread about dns issues with ovpn server in the mango and limevpn.
But this error message with protonvpn and udp is unique. I use udp with the mango and limevpn and I only find the dns issue described in the other thread. No error message and no interface blockage.