Authentification errors after connection

[Netzvamp]

Just for reference of a non critical error, that will be investigated:

Just after connection this can happen.

$ nc 127.0.0.1 29999
(press Enter)
{"error":"JSON decode error - Expected value but found T_END at character 2"}
{"playername": "someplayer", "password": "somepassword"}
{"error":"authentication error"}

Instead, this works:

echo '{"playername": "someplayer", "password": "somepassword"}' | nc 127.0.0.1 29999