Hi PoloZ4,
To clarify, have you already reset the AirPods? If not, we'd recommend doing so.
"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.
- Put your AirPods in their charging case, and close the lid.
- Wait 30 seconds.
- Open the lid of your charging case.
- With your AirPods in your ears and connected to your iPhone, iPad, or iPod touch, go to Settings > Bluetooth, or Settings > [your AirPods], and tap the More Info button
next to your AirPods. If you don't see your AirPods in Settings > Bluetooth or in Settings > [your AirPods], just go to the next step. - Tap Forget This Device, and tap again to confirm.
- With the lid open, 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.*

- Reconnect your AirPods: With your AirPods in their charging case and the lid open, place your AirPods close to your iPhone, iPad, or iPod touch. Follow the steps on your device's screen."
If the issue persists, also confirm your iPhone is fully updated to the latest iOS version under Settings > General > Software Update.
After that, contact Apple Support for additional assistance if needed.
Take care.