Sort by span title

Thank you for this great plugin!

I’m using it to sort a table on my website.

One column has only unsortable signs as content. However I’m trying to sort this column by value.

It’s the column IMDb here: https://flimmerzimmer.eu/filmothek/

So I added span title to the span with corresponding value but it’s not sortable.

Any ideas how to sort this column?

The page I need help with: [log in to see the link]