Google Cloud Print stopped working (previously worked fine)

Question

I successfully configured Google Cloud Print and has been printing from our website without a problem for weeks. This morning, I noticed we didn't have any orders printed. At some point last night it stopped working so I wanted to dig in to see what's happening.

I verified that my printer is connected. Looking at GCP console, I see:

Canon MX920 series_3673F2
Owned by me
Last print job was 3 days ago
Location not available
Printer is online and ready to print

This is not entirely accurate, since we had a variety of jobs printed yesterday/last night. So saying that the last print job was 3 days ago is not correct.

I rebooted the printer this morning, and still see it with 'online'.

I send a couple of test jobs and watch this via the GCP Print Jobs. I see it come in. I see it 'queued' and then disappear.

On the code side, I review the array coming back from the response. I do get a 'true' status and a print job 'id' is returned.

The job(s) that are printed reference PDFs that are created. I can confirm the PDFs exist and are readable and look good.

I also tested a straight print from my computer to that printer via LAN. All good.

I feel the code is running properly, and especially since I'm getting a 'true' response and job id from GCP. Any ideas where else to look?