'Local services turns yellow after printing job with more than 1 label, what could be the cause of this?'

The problem seems to be with the drivers of the network card (or file corruption after virus infection or outdated driver due to OS updates).
Using a traffic analyzer, it can be observed that the 3rd packet of the TCP session is not received every time, causing the session to terminate. "TCP segment lost missing 3-way handshake"

Installing the complete driver package for the network card from the manufacturer can resolve this issue; a Windows update driver package was not sufficient in this case. (ticket 99535, 94884, 99327)