PoE2 - Unable to equip skill Staggering Palm

After clinging in the details pane regarding which weapons to use the skill completely broke and won't let me add it to the skillbar (i.e. assign it to a button) anymore. I tried re-equipping it (and all other skills), restating the game, repairing the game (via Steam) and clicking around in the expanded panel again, but nothing works.

It will not get "picked up" when clicking it and is not available when clicking a button to assign it to. The expanded panel for the skill is also broken and shows either that it is not available, showing stata for the previously shown skill or shows a corrupt version with weapon sets I-IV with plus and minus signs left and right.

It's very annoying, to say the least. Fortunately it was not any of my critical skills!