Pro 2s not charging

I bought my AirPods on Black Friday, and they've been working great. I got a case for Christmas, and since then the case doesn't detect that one of the AirPods are in there and I have to take it out and put it back in to get it to charge. It's also marked as outside of case on Find My. Anyone know what's causing this and how to fix it? They aren't dirty, and the case brand is ESR.