Need help with Remote Syslog Settings

Question

Running UTM 9.5 and trying to use Graylog as a remote Syslog Server. I have configured both sides properly as far as I know, Graylog is receiving Syslog messages from other hosts but not from my UTM. 
 As soon as I save my settings I see the UTm connecting and inside Graylog I see the connection and yet no messages arrive. I changed the buiffer down to 10 lines in the hopes of speeding things up to no avail. 
 2018:04:05-09:55:54 security syslog-ng[5007]: Syslog connection established; fd='66', server='AF_INET(192.168.99.2:5140)', local='AF_INET(0.0.0.0:0)' 
 2018:04:05-09:55:57 security syslog-ng[5007]: Configuration reload request received, reloading configuration; 
 
 I have firewall rules to allow other machines to connect to Graylog on the port specified but I am unsure how to do this for the UTM, I mean what would be the source I select for a firewall rule, would my Graylog instance see the syslog packets coming from the UTM as coming from the Ip of the network interface where Graylog is connected to the UTM?

My settings: the host is configured via Ip and correct and the port used is TCP 5140. I also have Graylog listening on 5140 UDP but that also didn't work and worse, with UDP I cannot check see if UTM has connected or not. 
 
 Graylog sees the UTM connection

Any hints are welcome.

PreHCM-PK · Answer

Thanks! That pointed me in the right direction so after googling I found this solution: https://github.com/habibmbacfou/graylogzeus 
 
 Basically one needs to define a new input inside graylog of the type: RAW/UDP and import that selector then configure UTm to send to graylog on this port upon which all works perfectly! Unfortunately I canot mark your answer as "this helped me" as I keep getting an error telling me to report this to my moderator :-( 
 I can't paste a screenshot of this error as I get the same error again. The eyxact message is: "An error occurred. Please try again or contact your administrator."