The 860 EVO supports trim, in fact it should even work with the LSI controller, since it's a SAS3 model and the SSD supports deterministic read zeros after trim, you can try again after connecting it to the LSI but would be surprised if it worked, likely an issue with the SSD, not with the 860 EVO in general which is known to work with Unraid and used by many, but with that one, or an issue with the 860 EVO 4TB model in general, since there won't be many in use with Unraid.