Hotkeys jumping to bookmarks doesn't work

Hi! Sorry my english is not the best! I tried to use the hotkeys for jumping in between my own bookmarks, for example Play playlist bookmark 1 with F1 but nothing happened (beside that the help came up). I tried to assoziate others letters with the Hotkey and/or globel for example "1" but still no action and the "1" was not usable afterwords.

A buttom for next/previous bookmark would be very useful!