After the June update Spotify client for macOS has not connected any more. It is offlina all the time. This seems to be due to changes in the clients proxy handling.
Installing an older version helps until the automatic update kicks in.
Please revert the changes that broke the client.
Updated on 2018-08-13
Hello and thanks for the feedback!
This sounds more like an issue that's worth investigating.
Could you please search for that issue in the respective help section and provide more info about the issue. If it doesn't exist you can create a new topic and let us know about it! Then we can check it out there.