Spotlight battery one slot doesn't work unless other is in plsce

My Spotlight Battery won't turn on unless I have a battery in the right battery slot. It will not turn on at all with only a battery in the left battery slot. However, once I put a battery in the right battery slot it will recognize the battery on the left slot in the app. Also, when I put the left battery in, the red led inside the battery compartment does not come on. When I add the right battery first, then the left battery after, both red led's will come on.