Board Thread:Support Requests - Getting Technical/@comment-2056915-20151125052532/@comment-4142476-20151129083020

Well, I had never used "collapsible" without the mw- part so I had to look this up, but it might be this. According to that page, mw-collapsible is added by default in MW 1.18 or higher, and the "collapsible" class was added with Javascript instead to make collapsible tables work.

One of the things I noticed when comparing your table with Disney Wiki's, was that instead of Collapse/Expand, your buttons said Show/Hide. Those're autogenerated buttons, so I thought "if those are different, the underlying functioning is different"