Mobile Printing & Cloud Printing

My printer has stopped printing documents in colour from my PC, to which it is connected via Wi-Fi.

When opening the print menu, on the second page of printing options, I notice that "Monochrome" has become the default setting.  When I change it to "Colour" and click "OK" to return to the first page of options, if I click then print, I still get a greyscale document - my changing it to "Colour" made no difference.  However, when I open the print menu again, even for the same still open document, the output is showing "Monochrome" again.  It's as if the default setting has gone to "Monochrome" and will not accept changes, whether for one document or permanently.

I have opened every system settings or tools menu to do with the printer that I can find and I am unable to find anywhere where the default output (Colour/Monochrome or Greyscale/B&W) can be set, anyway.

I ran HP Print & Scan Doctor and it found no issues.  However, when I printed the offered test page, it was in greyscale.

I then looked at tools on the printer itself and followed instructions for printhead cleaning, which results in a test page being printed and that was in colour.  When I print via e-printing directly from my smartphone, it comes out in colour.

This is presumably, therefore, a glitch with the computer, rather than with the printer.  However, if required, the printer details are HP Office Jet 4658.  Please advise.