Hello Akkey73,
Thanks for trying our steps. I recommend the next steps.
Reset the AirPods to ensure the issue is not with them. Get help with your AirPods - Apple Support
"1. Go to Settings > Bluetooth and tap the icon next to your AirPods.1 Then tap Forget This Device.
2. Put your AirPods in the case and close the lid. Wait 15 seconds, then open the lid.
3. Press and hold the setup button on the back of the case until you see the status light flash amber a few times, then flash white.
4. Place your AirPods close to your device. Follow the steps on your iOS device's screen."
If the issue remains and since this only started after upgrading the iOS, I recommend making a backup of your data before the next steps. You can make a backup in iCloud or iTunes using this article: How to back up your iPhone, iPad, and iPod touch - Apple Support
After your data is backed up, I recommend reinstalling the iOS using iTunes. The reason we need to use iTunes for this step is to get a new copy of iOS installed to your device. Use this article to reinstall the iOS: If you can‘t update or restore your iPhone, iPad, or iPod touch - Apple Support
Please pay close attention when you reach step 4. Once your iOS is reinstalled, test if the issue is still occurring. Thanks again and have a great rest of your day.