You need to set the IP in the config file bnetserver.conf this is the reason for the disconnects when using the master branch because of new settings for LoginRest not to mention the new port for master branch port 1119. The ports to be open are 8085, 8086, 1119, 8081. The things to change in the config file are, because I take it you are trying to connect outside where the server is, which even if you are not this should be set to the correct IP's. When you open the ports that I mention you will ensure that the ports are now open for 3.3.5 and for 7.2.0 this way you can connect to either one.
LoginREST.ExternalAddress=xxx.xxx.xxx.xxx
LoginREST.LocalAddress=xxx.xxx.xxx.xxx