Stockfish the blunderer?

I was playing against the 3200 computer, and looking in the analysis to see where I was stomped and why.
The first thing that comes to my eye is that the computer had a 95.5 precision instead of a 100 (as you would expect from a machine); but then I see that he made a mistake in the recap and a couple of imprecisions (consider that it wasn't something like hanging your queen mind you, it was something extremly subtle).
Is there something I am missing? Shouldn't the computer play only optimal moves?
Or is it programmed to sometimes make random mistakes? But in that case if I want to play agains a perfect computer where should I go?

Maximum computer is enough to beat any human alive, even the best ones. But the chess.com 3200 engine is probably not the best engine you can play against. It also sometimes makes mistakes, but not obvious ones like hanging a piece or allowing an exceptional fork, but more positional ones