So I had been running Mojave and the HDD part of my Fusion drive on 2017 iMac 5K failed. I took it to local Apple Store to have the HDD replaced. I did ask them to reinstall Mojave but after a 12 hour ...
But therein lies the longstanding rub: an unresolved bug that spans many years. The big win of Apple’s photo screen savers is that they let you select photos from your Photos library or a folder.