Strange printer problem - explanation sought

In as much as a system restore solved the problem, below, I'd dealt with it. I just wonder if anyone can explain it and help me find a less drastic solution if it happens again...
My computer stopped printing to either of the attached printers. One wifi, one USB.
It had printed fine an hour earlier.
Other devices were printing to the wifi printer perfectly OK.
My PC could see both printers, and the printing appeared to be working as normal, but when I pressed print to either printer nothing arrived at either of them. It was as if the print jobs were falling down a hole on the way to the printer. I tried reboots. I tried stopping and restarting the print spooler.
None of those measured helped. Neither did the Windows Troubleshooter ( no surprise there ).
But a system restore to a known good restore point and it was fine again.
So, any ideas what might have caused this and whether there's a more specific way to resolve it. (And avoid it reoccuring)?
Win 10 Home 22H2
Processor AMD Ryzen 7 5700G with Radeon Graphics 3.80 GHz
Installed RAM 16.0 GB (15.9 GB usable)

Does Reliability History have any entries which may relate to the problem ?
In Powershell [admin ],type in ---dism /online /cleanup-image /restorehealth ---and when it has finished,then type in ---sfc /scannow ---and run it until a clean report is given.
Did you make any changes after the date of the successful Restore Point ?

"Reliability History" is not something I've come across before. Is it some kind of log?
Image clean ups and other such remedial actions aren't needed, since the problem is resolved. I really am just looking for an explanation or idea about how this could have happened.
Between that restore point and this happening I had changed my AV software. But it did not happen immediately. As noted above I'd printed perfectly normally an hour or so before. And several days later.

Have you tried uninstalling printers and reinstalling them?

No. That would only have made sense if one printer of the two had suddenly lost connection to the PC. But not when both, one Canon wifi one Brother USB are both being seen by the PC, but neither is receiving print jobs sent to them. And it happened to both simultaneously. Unless something could simultaneously corrupt two printer drivers, while apparently leaving them working- and if such a thing exists, that's what I'd like to be told about. There was no error. No printer was greyed out. Printer settings all came up as normal when selected.
Oh and nothing was stuck in the print queues.
So, the question remains; what could cause a PC to route print jobs into a dark hole instead of the selected printer.

Interestingly, the Reliability Monitor ( I hadn't come across this before) still has records of events from just before the system restore, e.g it logs my running the troubleshooter.
But nothing about the printer not working or any activity that would have diverted print jobs into nowhere, or anything.
But then the impression I have is that Windows' printing systems didn't think anything was wrong. Just that the print jobs all vanished on the way to the printers.

Using Restore Point eliminates everything done after that point was created.
Checking it now is mainly to see if there were any entries prior to the Point creation which need attention..Your printer problem occurred after the creation of the Point and remain unknown.