Last Lament + Choir Bug

The active skill on the Last Lament unique crossbow stops working and it's cooldown triggered when it isn't supposed to.

I've noticed this happens when a charm gets used while using the skill and I can't pinpoint why it happens in other instances (maybe a stun?) but during boss fights it will stop working and load in my siege cascade bolt right away.

Super annoying and when it happens in a boss fight right now I'm dead as that is my boss killing skill.