I think I have a solution, although not a completely satisfactory one.
I had noticed that there were 2 devices that show up for my Canon MG6220 - One that says Canon MG6220 Printer and another that says Canon MG6220 Printer WS. I had discovered this while trying to figure out why the printer was offline. I'm pretty sure that both of them said they were offline earlier this week. I decided that the WS must have been the one for printing via WiFi. I just learned that this is so from a post on the Canon website.
Just now, when I brought up the Devices page, I saw that the one without the WS was the default, as it should be, and that the one with WS was offline. I looked at the queue and saw that a number of documents that I had been trying to print, but couldn't, were in this WS queue, where they should not have been. A comment on the Canon website where I read about the WS versus non-WS device, said something that made me think to check the destination when the PRINT page comes up. There's a way to change the destination. You can't tell which printer device it's trying to print to because there aren't enough characters to display the entire name, but when I went to change it, the WS printer was on top, so I assume it was the one being chosen. I don't know why because the non-WS printer was the default. Having changed it once, it now seems to want to print to the correct one. This is all on Chrome because printing from Edge or Word was working. Why the Chrome browser software was choosing the wrong printer (just since a few days ago) is a mystery. But at least now I know that the problem stems from there being two printer devices (one virtual?) and that the wrong one was being selected.
Thanks for your help on this. I've spent way too much time trying to figure this out.