I recently had the same problem and was very dissatisfied with the solutions. Opening the browser is somewhat of a useless and annoying step.
To circumvent the bug in Spotify, I wrote a very simple application which fixes the bug. During testing, I found out that you can successfully open the playlist in Spotify when starting the Spotify app using an Android Intent. I used this to create the app.
When you're interested in the app, you can take a look at the instructions here. Feel free to write me, if you encounter any problems.