Canon ImageCLASS Color Lasers won't print

My shop had a Canon color laser printer that has been working well for a
decade, but after half our PCs had upgraded to Windows-11, it became
intermittently unable to print: For some PCs, Windows would claim that
the printer was offline. Sometimes it would work agin after power
cycling the printer. It seemed clear that this was a software/driver
problem. After trying everything I could think of for a couple of
weeks, I decided that I needed Canon helpdesk support, but I had no hope
of getting them to invest energy in an old, discontinued model, so I
went and bought a new model as similar as possible to the old one. In
fact, it looks identical, but the tomer cartridges have a different
number :-(

That was a month ago, but despite several hour-long support calls, the
new printer has the same kind of problems, except it fails more
reliably, and power cycling does not seem to help any more.
When I call tech support, their scripts eventually get it working after
an hour-long session. I print a few files, and say goodbye to the
helper. And the next day, the problem is back.

For a week, we went through a loop, where "making it work" included
having the printer get a random IP address from DHCP. Then I edited the
DCHP server configuration to put the printer on the IP address that we
have allocated for it in DNS, and then it would stop working.
Eventually, I picked a new "permanent" address for it and aligned the
DHCP and DNS addresses to that IP. And it worked for a week ...

In the old days, one could define it as a "generic postscript printer"
and load a proper PPD file, but I can't seem to find a PPD file for the
current Canon printers.

My current working hypothesis, is that the faily recent drivers
fail to relese the TCP session at the end of printing, thus preventing
the next user from connecting from another device. It might even be on
the printer side.

Should I just take this printer back to BestBuy for a refund?
And if so, what is a better printer for my environment?

I need to use this with:
- permanently installed Windows-11 desktops
- ambulant Windows-11 laptops
- a Linux server running CUPS
- a couple of old desktops in a lab running Windows-7
- and if possible, AirPrint from a few iPhones (old one did not do that)

It is a sad fact, that there seem to be no good printers anymore,
with the possible exception of monochrome lasers.

I know that for anyone to actually help, I need to give model
numbers, driver versions etc, but I am posting this from home,
and that info is at the office. I will add that in a follow-up if
anyone here thinks they have ideas that require it. Right now I am
hoping to hear from anyone that has experience with these printers,
good or bad.

-- 
Lars Poulsen - an old geek in Santa Barbara, California