Radio works but not able to preset radio stations. I follow manual instructions with no results.
Unusual at only four years old, but you may need a new unit. At the minimum I would check with a Ford dealer, there might be an update or TSB for your radio.
TSBs are not recalls, the cost most likely will be on you. The other option is to talk to a shop that sells and services automotive infotainment systems.
Is there a separate fuse for radio memory?
Like @NYBo , I also wonder about the memory fuse, which should be in the panel under the hood, as the cause of this issue. If the clock inside the unit doesn’t keep time that would be a sure clue the memory fuse is most likely blown out.