That is most definitely a local issue, I can take any version of the engine that I have a current installation of the compiler that will work with it, and have it running on a similarly spec machine in 45 minutes (assuming you have NVMe SSD storage, as well)
20-minute compile times are not normal – on a machine like that you can build the entire engine+editor in 45 minutes on a clean build. I know, I do it regularly.