Regex (JS) - match any combination of 5 characters, but ignore 5-character repeat

I am struggling with regexes and I am trying to create one that can match any combination of 5 characters X

and O

, but ignore it if it repeats X

or O

EXACTLY 5 times.

This is what I came up with:

X{1,4}|O{1,4}
X|O{1,4}

      

        
        
        
      

    

these expressions match (I want it to ignore XXXXX and OOOOO):

I also tried using a non-capturing group, (?:)

but that didn't work too well.