[Plugin: Better Search 2.1.0] Boolean Operators Are Being Stripped Off

I just upgraded from Better Search 2.0.1 to 2.1.0. Boolean searches have stopped working properly. On 2.0.1 entering +education +martinez returns exactly one item (which is correct). On 2.1.0 the same search returns 9 items (which are all the items containing “education”, which includes the one containing “martinez”). When I look in the search again field where the search argument is displayed, I see that the + signs have been stripped off – so it actually searched on education martinez (logical or).
How do I fix this?
Barry