I'm working on Big Sur 11.6 with a Brother HLL23500W printer, connected over wifi.
If I print a multi-page document, very often the printer will print the first page or two pages, but then stop, with this message in the print queue:
Unable to add document to print job
There are no hardware or paper problems with the printer, and it will happily start printing another document.
I have no idea how to debug this - any ideas how to start?