on the Android there is Config/Networks /VPN. One can provide name, type, server, encryption. Mikrotik allow to connect via VPN. So on the mobile I just provide VPN required info, uname/login and run. I am connected to my router, can print on my home printer…But also I can see Internet, filtered by my firewall. Until I switch to OpenDNS…
Configuring OpenDNS must have change the configuration so VPN incoming connection can not see the Internet. If I restore previous configuration on Mikrotik my phone can see Internet. I change nothing on my phone, only on Mikrotik. But the phone is affected.