Two of the key bindings of MarkdownEditing are colliding with the key combinations for polish diacritics "ś" and "ł", typed with Right AltS and Right AltL. When pressing the above key bindings the actions sort_footnotes and list_markdown_references are triggered.

Seems like Sublime is treating pressing Right Alt the same way as ShiftAlt, at least when the "Polish Programmer's" keyboard layout is selected.