I tried that as well and the same thing happened. Mine was an original so I don’t think it’s an issue with cover songs.

Having the same issue

When you go to post, if you switch it over to photo (confusing because it looks like it’s on photo by default but it’s not) it seems to have worked for me, kind of annoying because you also have to post an image with it. I messaged support, we will see if they get back to me.

Also just realized the mobile app works for links, I had been trying the web browser version of the site before.