I have been having the EXACT same problem. I can find about 75% of my friends' starred lists and follow them no problem. I have tried to find a way to either share or make my starred list public for a long time. It's pretty frustrating.
I just thought of an idea, I'll let you know if it works. I wonder if there is a way to change the playlist's settings on the mobile app...?
So I went on the mobile app, and clicked on the "three vertical dots" next to my starred playlist to bring up the menu, and then clicked "Publish". After I published the playlist, I was able to use the share function...but only on the mobile app. I still don't have a share function on the desktop app. Also, this still did not make my starred playlist a public playlist on my desktop app, but you can share it with followers at least.. = \