What is tha little sort icon next to one of my favorites?

That means you probably switched to a different sort order for that favorite. You can change it by tapping the three dots on the right and choosing "Update sort" (in my case the resulting dialog box looks weird/buggy, but choosing "update sort" again lets me change the sort for that favorite, while choosing "cancel" on the far left removes the custom sort and goes back to the default of Active which also removes the icon you saw).