Bug: 'Summon Spectral Assassin' equipped in left and/or right hand

[Konrad]

I got the 'Summon Spectral Assassin" power from the quest "Bound Until Death". But if i try to equip it, it slots into the left or right hand(Arrow with"L" or "R"), instead of equipping like a Shout or other Power. (Hollow Arrow without letter)

Attempts to use it with left or right hand result in a default Summon/Conjure effect seen in other conjuration spells. But instead of the effect occurring at or near the cursor, it centers on the player. After that, nothing happens, the usual Specter of Lucien Lachance does not appear. But the 24-hour cooldown on the power does trigger.

No mods installed, playing vanilla Special Edition with default DLC and CC content.

Attempts to fix issue:
- Restart game.
- Remove power with console commands.
- Combinations of the above using separate saves for each step.

All attempts didn't fix the bug.