Highlighting Problem

Hi, I have got a problem with the highlighting in Relevansi that I am hoping someone can help me with.
– I have the background colour highlights turned on for the search term in both the search results and the landing page where you go after selecting a search result.
– I am using the search term for example ‘locked in a race’.
– There are four exact matches of this on the website and lots of occurences of ‘locked’ and race which are getting picked up too.
The Problem: The highlights are highlighting all the ‘locked in a race’ occurences, which is what I want and I wouldn’t mind too much if it highlighted occurences of ‘locked’ and ‘Race’ but it is highlighting all the occurences of ‘in’ and ‘a’ which just leaves a sea of messy and basically useless background colour. Is there some way I can make it just hight light exact matches of the search phrase?

Thank you very much for your time in advance.

https://wordpress.org/plugins/relevanssi/