One problem is that 'LakeO' is a substring of every string in @updateloc1. The regex /LakeO\b/ matches only with 'LakeO/stuf' because the latter string has a forward-slash ('/') in just the right position to match with the \b word-boundary metacharacter in the regex. Why it matches with the use of /g (if, indeed, it does) I will not be able to figure out without the ingestion of a lot more caffeine.

What is your definition of exact match in the context of the example you have given?