Left AirPod won’t charge

my left AirPod won’t charge more than maybe 5% while my right AirPod charges just fine. Sometimes my phone will say that my left AirPod is charged up to 100%, but if i try to use it, it will die within around 3 minutes. I know this isn’t a problem with the cleanliness of my AirPod or my case because i clean them regularly so what’s going on and how can I fix it??