Connecting 3 monitors to macbook pro 2018 via thunderbolt 3
For anyone trying to do this using a dock that has multiple display outputs, the MacBook Pro 2018 only has two thunderbolt busses, but 4 ports (2 ports per bus), as a result, if you try to connect three external monitors, you will need to use different sides of the device.

If you try to connect all three monitors into two ports on one side, it won't work.