And FWIW, attached is an end-of-log extract of creating a driverless IPP printer ("cupsweb3") from cups web interface, then printing a test page. Again, s-c-p reports job completed, but nothing printed.
There are continued references to "ipp/faxout" - and no references to ipp/print. Eg: line 2584 D [28/Jun/2022:02:55:42 +0100] [Job 42] Calling FindDeviceById(cups-cupsweb3) 2585 D [28/Jun/2022:02:55:42 +0100] [Job 42] Resolved as \"ipp://mfcl2740dw.local:631/ipp/faxout\"... Might this be relevant? Thanks, Gareth
cupsweb.txt.xz
Description: application/xz