That's interesting & somewhat surprising, we are currently testing a Canon MAXIFY GX5020 and everyone in the office hates its color output. It's in the same MegaTank family that your Canon is in.

I'm trying to figure out if maybe Canon sent us a bad printer or if these Canons just don't do colors that well. If you have a chance can you do these two color test prints & let me know how yours does?

https://cmyktool.com/cmyk-test-print/ (download the PDF and print it)

https://printtester.com/#print-color-test-page (download the Color Test Page PDF and print it, the one with the color wheel)

What I've found is that our Canon does fine with the CMYK Test Print but doesn't do as well on the Color Test. For us in the color wheel when the colors blend from Blue into Red (e.g. the dark blue / purple / dark red) the mixed colors look sort of dull and generally off. So any images with purple or around that color come out sort of darker/dull compared to our old color laser printer. I can't really explain colors that well but you get the gist :D

When we first received the printer magenta was barely printing so all the colors were especially bad, after doing the printer maintenance functions that color at least started printing but I wonder if the printer heads are just screwed up on this one, hmm.