I adopt Religious Hostility civic to generate a grievance with all adversaries that have a difference religion.

Next turn I obtain the grievance.

I demand that the Persians convert to my religion and they cowardly accept.

Next turn I get another grievance saying that my previous grievance "is no longer possible". So I can demand money instead.

While this is great for me since I want to go to war, it is clearly a bug.

No grievance should be generated if the civilization accepted the demand.

Celts Turn 129 - religious grievance bug.ctr