Once an index started moving through the phases of an ILM policy I can attach a second policy to the same index. Once this happens I cannot remove ILM policy from the index. I was able to attach the original policy back and then remove the ILM policy. I doubt this is intended behaviour
Which policy are you referring to, the new one or the original one?
Using the API call - POST <index>/_ilm/remove I'm not sure which policy it tries to remove. It just times out, doesn't give an error