Hello:) Read through this info:
If I'm understanding you right, you don't get audio from your AirPods unless they are positioned so they pointed in a specific position that isn't the correct way to use them. I can see how this would become bothersome, and I'm happy to help you get this resolved so you can enjoy using your AirPods again.
First, I recommend making sure the speaker mesh on your AirPods is clean and free from any dirt or debris. You can view the correct way to clean them here: How to clean your AirPods and EarPods. Next, put both of your AirPods inside of the case and open the lid. On the iPhone they are connected to, go to Settings > Bluetooth, and tap on the "i" symbol next to your AirPods. Enable Automatic Ear Detection if it isn't already enabled. If it wasn't already enabled, test out your AirPods after enabling it to see if you experience the same thing.
If the issue persists, take only the left AirPod out of the case, and then hold it placing your fingers on the in-ear sensors (These are the small circular holes you see on both sides of the AirPods.). Play audio from your iPhone while still holding the sensors. Check to see if your AirPod was automatically selected as the audio output source on that iPhone. Reset your AirPods next using these steps: Reset your AirPods. Test out your AirPods by using them like you normally would. If none of these steps help you may want to contact Apple Support through link in article.
~Katana-San~