i can confirm it is somehow related to the server address.
i just started a local server and the client with the following addresses as favorites:
seta server1 "10.43.38.192:27961"
seta server2 "localhost:27961"
seta server3 "192.168.44.241:27961"
seta server4 "127.0.0.1:27691"
the interesting find was that the serverbrowser works as expected for server 1+3.
for server 2+4 it just displayed no response.
i will try to verify this on my other setup.
is there anything else i could check/verify?