Weird, hard to diagnose printer problem

[Baby Lee]

It prints fine from the printer menu, but will not print black from the PC

I have a Hewlett Packard Photosmart 8450, and I'm in Win10 with all updates, including Creator's Fall Update. It's an older model, but has never given me any problems.

As recently as earlier this morning, it printed everything fine, but I was getting 'ink level low' notices. I had some important [quality-wise] printing to do, so I replaced cartridges [Black and Photo only, I replaced the Tri-Color a month ago without incident]. All replacment cartridges are genuine from manufacturer.

Now everything prints fine if I select it from the onboard menu [alignment page, cleaning page, test page, etc], but if I print from anything in Windows, it goes through the motions of printing everything, but there is no black output.

Based on the cleaning/alignment results, I'm fairly sure it's not a hardware problem, but I've having trouble finding a software solution. Some said random unplugging and replugging [both USB and power]. Some said wait a day. Everyone else seems to have print head problems, which is highly unlikely here as mentioned above.

Just curious if anyone has encountered anything similar.

EDIT TO ADD: I should say, I changed the black cartridge and printed a few pages fine including black. Then I changed the photo cartridge and the black stopped printing after that.

Timeline
1 week ago - replaced tri-color
through past week - low ink notice, but printed plenty of things fine
early this morning - replaced black cartridge, printed a couple more pages fine
later this morning - replaced photo cartridge, printed test and cleaning pages from printer menu fine. No black output from PC.