Where: Anywhere.
When: When your PC fails its will save and you come under the influence of fear. Frequency = always.
What: Your character continues to run around like a headless chicken after clearing magical fear by methods that remove magical fear or the fear affect expiring, which often overriding your commands. This results in unjustly receiving further attacks of opportunity, running into traps, and generally bad tactical actions.
Recreate: Have hostiles attacking. Be feared by a fear aura or spell. Have Remove Fear applied to you either by potion or spell, or wait for controls to return to your character. The AI applied to your character then continues to (poorly) navigate your character, interrupting your own choices.
Ideas: The fear mechanic is an exercise in frustration, regardless of bug or not. Suggest either fixing the bug or removing AI-based character control entirely and instead apply debuffs to attack bonus, armour class. attributes, skills, for the duration of the fear influence to compromise reworking the frightened/fleeing state.
NWN fear spell (applies frightened)
NWN frightened condition3.5 fear spell (applies panicked, not frightened)
3.5 frightened condition