Maybe you are affected by a problem fixed in the code base of IMatch 2021 (and the corresponding compatibility update for IMA which will be released at the same time as IMatch 2021).
See the end of this thread:
https://www.photools.com/community/index.php?topic=11264.0Unfortunately it is not viable to roll-back these code changes and 3rd party components back into the IMatch 2020 / IMA 2019 code base.
If you are affected by this rare bug, you should setup ONE category which contains only the files you want to make available, and then set the ACL to this category.
Combine @Label and @Rating in a formula, check the result is what you expect, set the ACL to that category. This will also be faster during runtime.