A very weird post but bear with me. I tripped and my AirPods ended up out of the back door into a puddle of mud. I gave them a good wash in the sink and left them in a warm room to dry off. After a week they still didn’t sound right, podcasts were fine but when it came to music they sounded terrible.
Well the good news is that now 5 weeks later they have suddenly sprung back into life and I have bass back. They sound just like they did before my little accident.
So the morale of this story is that if yours do get wet and sound terrible give them time to dry out. Charge them in your case and keep using them, they’ll sort themselves out.