Disc Printing offset on Canon Pro-10

[MattRamsey]

First time attempting discs on the Canon Pixma Pro-10, results as pictured (and others, printing at various scales and positions all over the discs.  Any experience or suggestions?

Using My Image Garden 3.6.8 on Mac OS Sonoma 14.0 (M1 Mac).  Print dialog makes me choose a paper size larger than 4.7" inches to enable the "printable disc" media type options (grayed out otherwise), so I created custom paper sizes at 4.7"x4.7" and some others attempting to counter the offset, but everything larger than 4.7" makes the problem worse.  Updated drivers and printer firmware today as a last resort but no difference; printing via USB.

(Does continue printing past the disc edges, onto the tray, making a huge mess).

Thanks for help!