Hello mouseone,
If your left AirPod isn't working as expected, please be sure to review all of the information outlined in the link you came from, which can help if one AirPod isn't working as expected: If your left or right AirPod isn't working
If your AirPods aren't connecting, please check out this link, which has some suggestions that may help with connection issues: If your AirPods won't connect
If you can't connect to your iPhone, iPad, or iPod touch
1. Make sure that your iPhone or iPod touch has the latest version of iOS or that your iPad has the latest version of iPadOS.
2. Put both AirPods in the charging case and make sure that both AirPods are charging.
3. To make sure that Bluetooth is on, go to Settings > Bluetooth.
4. If your AirPods are connected, make sure that they're selected as your audio device. If your AirPods appear in the list of devices but they don't connect, go to the next step.
5. Close the lid, wait 15 seconds, then open the lid. Press and hold the setup button on the back of the charging case for up to 10 seconds. The status light on the front of the charging case should flash white, which means that your AirPods are ready to connect.

6. Hold the charging case, with your AirPods inside and the lid open, next to your iPhone, iPad, or iPod touch.
7. Follow the steps on the screen of your iPhone, iPad, or iPod touch.
8. Test your AirPods. If you still can't connect, reset your AirPods.
If you need additional assistance, please contact Apple Support for help. You might be able to reach them here: Get Support
Thanks!