GameplayAbilities questions

So I’m past all the targeting issues and have a few abilities working as expected in the game now.

I’ve hit my next roadblock, however. How do you end an ability from outside of the ability itself? For example - The AI changes targets, which requires the ability to be restarted due to internal state of the ability needing a reset.

I’ve tried using UAbilitySystemComponent::EndAbility(FGameplayAbilitySpecHandle AbilityToEnd) with the handle that I use in TryActivateAbility, but it doesn’t seem to stop the ability. Any ideas where I’m going wrong?