While I do like the Canon's I've had over the years the usual complaint I get is after a few years when a driver is no longer updated.
That is, if you had a non-functional MF printer it's no big deal if it doesn't work as you pack it up and exchange it for a working one. This is why I wonder if your troubles are the usual. That is, years later.
I have had a lot of trouble with multi-function printers interfacing and playing well with my IMAC sometimes they won't print, wont scan or work at all. I was told by a Machead that there are certain brands that work well any recs?