How to overcome slow printing to a network printer?

Question

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Good afternoon. Help Wanted. After some time on a PC (both Win7x86 and Win8.1X64) printing to some network printers becomes very slow (it happens that the collation does not go one after another). Raised print server on Windows Server2012R2, the whole zoo of HP4300,HP4350,HP4515,HP M607 printers. All drivers are official PCL 6 (not a universal driver), driver type is V3, direct printing is installed on all printers, "shared access" driver isolation. Printer client machines are installed via GPO.
This kind of situation, PC1 quickly prints on HP4300, HP4550, HP4515 and even on HP M607 No. 1, but on HP M607 No. 2, when you click on print, the print window in Excel may hang for a long time and printing as a result from HP M607 No. 2 will come out on 1 sheet at intervals of seconds 3. At one time, PC2 prints quickly to all printers. The PC bundle is the same and the software package is the same.
What was done: All drivers were removed, connected to a direct printer both via a network and via a USB cable. Cleaned the spool folder. Removed the printer from the registry.
It helps only restore the system to an earlier date. Where to dig next? Thanks in advance.