Thank you. After battling with Safari instead of Chrome, which made the printer work but was desperately slow overall, I decided to delete Chrome entirely and reinstall it but to no avail. I therefore also reloaded the USB printer driiver (not IJ) on...
My MX535 has just started to do the same, after changing the scale from custom 200% back to default. It still prints correctly however if I do it using Print Through System Dialogue. All settings are default and the page size is correct at A4
