Can you please test/answer these:
– Is this happening on the live results list?
– or is it happening on the results page only?
– Do you have any other search/filter or any similar plugin installed?
– If you switch to the default theme (twentytwenty), does the issue continue?
– If you turn off all off the plugins, does the issue continue?
– If you create a new search bar, and not change any of the options, does the issue continue? (test both live and results page)