Mac Editor Server <-> Mac Editor Client communication failures

[SoftwareGuy]

Unity version 2018.2.20.

It seems that if you try to connect a Unity Editor that is in client mode to another Unity Editor instance that is in Host mode on the same computer (127.0.0.1/localhost) then the Unity Editor in client mode will not be able to connect to the localhost server counterpart.

Originally reported by Miles Every on the Discord. Confirmed that the bug exists by testing and can replicate the issue locally on my MacBook Pro.

Reproducible using the project (download it here). Open two Unity Editors with the project (you might need to make two copies of the project, since you can't have two editors open on the same project files). On one editor of the project, open the Pong scene, click "LAN Host". On the other editor, open the same scene and choose "LAN Client". This will attempt to connect to localhost... and should fail. The Peer object while it's in this state is stuck on "Connecting".

Does not seem to happen if you connect to a Windows Editor instance from the Mac Editor as a client. Windows Editor to Windows Editor instances are literally bullet-proof.

[SoftwareGuy]

Tested and confirmed to be fixed along with some other oddities that have been fixed as well in v1.0.9.9+.