He needs time, I was never gonna judge him this season.
That being said, his position is pretty flexible right now, not sure he yet has a best position, but it seems like RW is where the minutes will come from, it's where he gets them from Spain.
Now in Spain, the RB overlaps much more than Cancelo does, letting him play "inside" more. His games for Spain pretty much are summed up like this:
1) Ferran wide, Ferran will cross. His crossing is also very good, but he didn't do that much today.
2) His fullback wide, Ferran comes inside. Play develops on the left and he looks to find space to get a shot across. Our fullback wasn't wide enough to let Ferran play inside enough, when he had the chance later on he scored.
He probably can be better as a False 9 with KdB, which I'd like to see, but RW is where he needs to improve right now.