Can't bind UDP socket but port is free

I've been struggling for a while now with this so maybe someone here is able to help me.
I'm setting up a CS:GO server that's going to be running on port 27059.
(This is a copy&paste from a working server, so I'm not posting config files used)

When I try to start it, I get this error:

WARNING: UDP_OpenSocket: unable to bind socket

Which basically means that the port is already being used, so I do the following:

Stop the server
netstat -punta | grep \.27059 # I get nothing
Start the server
netstat -punta | grep \.27059

And get:

tcp        0      0  192.0.2.178:27059     0.0.0.0:*               LISTEN      21932/./srcds_linux
udp        0      0  192.0.2.178:27059     0.0.0.0:*                           21932/./srcds_linux

So it looks like the server is actually being able to use that port but, somehow, I keep getting the same error.