A printer that works random

I have a Lexmark M410 connected to a LAN with a NIC and a static IP Address to print packets from Unix programs and connetecd directly to a Pc via parallel port to print via Microsoft word documents. The printed is shared with another Pc in the lan using the driver Microsoft.
The print start to print by otself without any user request a couple of control character when a pc is turned on.
What can I check via software? The printer in properly configured via its panel and internal settings are all Ok.
There’s a strange broadcast that I not founding…
Tks
Andy