Like @ScottWorld says, your field Category doesn’t add upp to just “macOS”, it adds upp to “Application, macOS” which is not the same and Airtable, correctly, doesn’t apply the rule.
For this you need to use FIND(), so each time it finds that category anywhere (as first, second, :nth) it will apply the rule.
In your screenshot the checked checkbox field is not called either “Universal” or “Intel”, but I asume that is just a screenshot matter. If not, you need to make sure that the name of the field matches the name in the formula exactly.
Like @ScottWorld says, your field Category doesn’t add upp to just “macOS”, it adds upp to “Application, macOS” which is not the same and Airtable, correctly, doesn’t apply the rule.
For this you need to use FIND(), so each time it finds that category anywhere (as first, second, :nth) it will apply the rule.
In your screenshot the checked checkbox field is not called either “Universal” or “Intel”, but I asume that is just a screenshot matter. If not, you need to make sure that the name of the field matches the name in the formula exactly.