Hello
Usually slow printing problems with network printers are related to the network, the print spooler, or the printer driver.
Now that you have tested Canon, Brother, HP and other printers all have very slow printing speeds under the same network, you can basically rule out printer problems and driver problems.
It is recommended to test network problems first.
Secondly, check the printing speed of the same network printer connected to other computers.
In addition, the operating system is updated to the latest.
Best Regards,
Wesley Li