The count will not always match the number of sentences shown as a word or phrase can appear more than once in the context sentence or paragraph. For example, say you’re looking at the Adverb results for the word suddenly. The count shows 10 and when you click on suddenly you see only 7 sentences. One of those sentences has 4 instances of the word suddenly, all shown in bold.
In this case, the count of 10 is correct — the 7 results contain all 10 instances of the word suddenly. The alternative would be to show the same sentence result 4 times in a row.