With recent updates, I noticed that when printing to Prusa i3 MK3S with MMU2S, it asks me to pick filament from 1-5. I select it but then it goes ahead and try to load the filament all the way to heater block. Since I just hit print and heater nozzle is still cold, it keeps forcing to feed it through many times. After min or so it finally gives up and retracts. Little while after that, printer is heated up and ready to print so it'll feed again.
I think the selection of filament during initial print is a good feature but I think actual loading of the filament should be only done once the temperature reaches the optimal temperature.