Very strange CUPS problem

I have a networked printer at IP 192.168.0.250 that I am trying to print to from my Fedora host at 192.168.0.210. It appears that the jobs are succeeding from the CUPS side, but nothing is being printed on the printer. Printer is brand new (I got a new one yesterday after I was seeing similar problems on my old USB one), and has paper, ink, etc.

I put log level on CUPS to "debug" and so it is rather long. But here is the pertinent section:

Does anybody have any ideas on how to even begin debugging this problem?

Thanks in advance for any replies...

Further update for anyone that runs into this issue:

The problem resolved itself when I installed the "hplic" drivers. This has a whole bunch of dependencies, and so ended up installing a lot, but the setup now seems to work with the drivers provided by "hp-setp" binary that gets installed with the hplic package.

Further note of caution:

I was using both a network (hp) printer as well as a USB one (both Deskjet series I believe), and whereas hplic provided the correct drivers for the network printer, but the issues with the USB printer still remain (although hp-setup was able to find that printer and reported successful completion).