LUT management is very challenging within Premiere. Many users try to simply place the LUTs inside the folder rather than import them via Pr which leads to instability.
Recently I reopened a job (that was finished 2 years ago) in order to create language versions and the LUTs were not in the same order as the new version of Premiere. The wrong LUT was being used in the new Pr version. I believe it is something to do with the numbering order of the LUTs (just a guess).
What we need is a reliable LUT management solution which would be driven via the CC Assets Panel. That way, by having the management handled external to Premiere, we can rely on the file structure over time and new releases of Premiere.