Thanks for letting us know, faengelm,
What type of headphones are you using? You can learn more about which headphones are compatible with announcing notifications via Siri here: Announce notifications with Siri on AirPods or Beats - Apple Support
"If you don’t hear Siri announcements
If you don’t hear Siri announce your notifications, try these steps:
- Make sure that you're using a compatible device.
- Make sure that your AirPods or your compatible Beats headphones are paired to your device in Settings > Bluetooth.
- Go to Settings > Notifications > Announce Notifications and make sure that Announce Notifications is turned on.
- Make sure that your iPhone or iPad is locked and its screen is dark. Siri doesn't announce messages if you're using your device."
We hope this helps.
Take care!