both airpod pros are fully charged and left airpod will not connect either through phone or ipad.

Hi dipped-in-ink,

Thanks for connecting with us here in Apple Support Communities. You've reached us from a great article about what to do when having issues with your AirPods: If your left or right AirPod isn't working

Were you able to follow all those steps including resetting your AirPods as doing so may help to resolve the issue you're facing. See: How to reset your AirPods and AirPods Pro

How to reset your AirPods and AirPods Pro

You might need to reset your AirPods if they won't charge, or to fix a different issue.

1. Put your AirPods in their charging case, and close the lid.

2. Wait 30 seconds.

3. Open the lid of your charging case, and put your AirPods in your ears.

4. Go to Settings > Bluetooth. Or go to Settings > [your AirPods].

* If your AirPods appear there as connected, tap the More Info button  next to your AirPods, tap Forget This Device, then tap again to confirm.

* If your AirPods don't appear there, continue to the next step. 

5. Put your AirPods in their charging case, and keep the lid open. 

6. Press and hold the setup button on the back of the case for about 15 seconds, until the status light on the front of the case flashes amber, then white.*

7. Reconnect your AirPods: With your AirPods in their charging case and the lid open, place your AirPods close to your iPhone or iPad. Follow the steps on your device's screen.

Kind regards.