How to Fix Canon 2420 not Printing Regularly?

Good afternoon. The organization has 10 Canon IR2420 printers. Printing is set up over the network via a print server. The problem arose a few months ago. The print job hangs regularly, when the job is deleted and reprinted, the job also hangs. At the same time, the printer pings, I go to the printer's web page. This task is not in the printer logs. And on all printers in random order. After the printer is turned off/on, hung jobs are printed. Some time prints normally (day, two, week). What did: 1. Changed patch cords 2. Reset devices to factory settings 3. Set the IP address manually, not by DHCP 4. Updated the driver 5. Connected directly to computers, bypassing the print server 6. Used a computer outside the domain. Help me, please!