no power but lights work

Hello. I have a 2014 EZ-GO RXV electric golf cart that runs on 4, 12V batteries. I just replaced the batteries, and they’re fully charged. The lights and USB port work fine, but the cart won’t move (and the battery charge-level gauge doesn’t work). I’ve tested all batteries individually to ensure they’re all showing 12V, as well as tested the series to ensure it’s producing 48V. I’m completely stumped at this point. Any thoughts?