I have the same problem for months.
At the begining I thaught its the falut of my connection but there is some problem outside.
Rejoining to the server helps for a moment but not awayes.
I agree that aproaching battlezone often triggers this effect that can last even if you leave the zone or system.
Server restart helps.
If you are running Windows Firewall, try removing all references to Freelancer from the authorized applications.
This will force the Firewall to redefine the rules for it, meaning that it will ask for permission like it is the first time you are running the program.
I am also more consistently getting lag and loss since about a month ago I was not. biggest problem seems to happen specifically when going to some Battlezones such as Coronado and Zeta
