Why won't my AirPods Gen 2 connect?

Last week I found some AirPods (gen 2) in a creek by my house. Everything seemed normal, I soaked them in rice and let them air out. I went into charge them which worked, and connected them to my phone, which also worked. But then overnight the case just stopped charging. I got a new case that works, but now there’s a flashing green light on my AirPod case. Help.