I'm stumped by a recent rash of macOS (BYO/unmanaged) client mapped printer print failures lately.
Jobs are making it all the way to the endpoint (app creates the print job, Windows spools it, VDA sends it to CWA, CWA sends it to CUPS, but CUPS GUI on Mac endpoint is showing all jobs as cancelled.)
FWIW, we're still doing the "legacy" HP LaserJet 2800 PS print flow vs Citrix PDF/UPD printer.