as suggested, if you right-click copy the object and then paste into notepad you can see the multiple identical tags
InternalTags=(InternalTags=((InternalTag="/Script/Solaris.VerseClass'/MyLandscape2/_Verse/character_tag_a.character_tag_a'"),(InternalTag="/Script/Solaris.VerseClass'/MyLandscape2/_Verse/character_tag_a.character_tag_a'"),(InternalTag="/Script/Solaris.VerseClass'/MyLandscape2/_Verse/character_tag_a.character_tag_a'"),(InternalTag="/Script/Solaris.VerseClass'/MyLandscape2/_Verse/character_tag_a.character_tag_a'"),(InternalTag="/Script/Solaris.VerseClass'/MyLandscape2/_Verse/character_tag_a.character_tag_a'")))
If you use tag_search_criteria then you will get the correct number of objects (in my case 5) but fundamentally this needs to be fixed because the overhead of all these tags is too much and increases exponentially for each object included in the tagging process
myTaggedList := GetCreativeObjectsWithTags(
tag_search_criteria:
RequiredTags := array{character_tag_a{}}
)