The switch is already a fact, a day earlier than announced. We are transferring our internet (and also TV and telephone) from Ziggo to NLEx. The latter is cheaper and we are done with Ziggo's selective disconnection behavior.

Things like this never go smoothly. A different provider is a different router. I declined the offer to send a mechanic over. They will probably be good at plugging in plugs, but I can do that myself. The problem with the ZTE Experia V10 that we got from NLEx is that you can't use static IP addresses. It all worked, but the server was unable to establish outgoing connections. It must have got its IP via DHCP, otherwise, the router will say "I don't know you". Everything else runs smoothly and at least as fast as at Ziggo.