We have the same set-up [B&G 4G RADAR and Zeus2 MFDs.]
Our RADAR seemingly stopped working once a couple of years back. It turned out that the RADAR ethernet cable [yellow twist-on caps] was routed through the GoFree Wifi1 device to the MFD, and the GoFree suddenly decided not to pass through the ethernet traffic. Bypassing that device [i.e., going direct from the RADAR black box to the MFD] solved
the issue. [As did a new WiFi1 replaced under warranty...]
The lesson learned was to also check/ experiment
with the ethernet cabling and routing.
In case this is helpful, and good luck resolving the issue.