About GameplayEffect modifier's tags

I have found that SourceTags and TargetTags field in a GameplayEffect modifier do not work as expected, even if I have set some tags in SourceTags like below, this modifier can still be applied to target who does not have that specific tag. Am I missing something or is it an engine bug? Thanks a lot!
PS. I know that I can set “ApplicationTagRequirements” to prevent this GameplayEffect from applying, but this is not what I want to achieve, I want that this GameplayEffect to be always applied but modifiers within this GameplayEffect get applied based on its individual tag requirements…