Compared to the previous times we moved house, getting the internet working at the new house was relatively frictionless. What annoyed me the most is that they sign you up to a completely new 18-month contract at higher prices, or you have to pay exit fees in the hundreds of pounds. So they basically have you between a rock and a hard place.
One issue that I have is that our new house, built more than a century ago, has stone walls. WiFi does not penetrate very well through stone walls. The two copper wires that are used to provide our "superfast fibre" internet terminate on the ground floor, while my home office is on the first floor. I'm lucky if I get 10Mbps in my office, while I'm paying for 76Mbps.
My first step was to swap out the ISP-provided router for a proper ASUS DSL router (with three massive antennas on top), but while it now provides better WiFi to the upper floors, it's still pretty slow in my office. After switching to the ASUS router I had to spend 40 minutes on the phone with the ISP to get everything working again, but that's a whole other story.
The next step is to get a WiFi extender, and if that fails I'll maybe get another ASUS router to try out their new AiMesh technology. I want to try powerline networking plugs, but given the age of the house I doubt that the electrical wiring will be up for it.