Siri not responding when the screen is locked

I have always been able to use Siri while my screen is locked. I’ve had this iPhone 14 pro since 2023 and Siri was working fine.

Yesterday, without making any changes, Siri suddenly stopped responding when the screen is locked. I tried restarting Siri, restarting the device, and even updated the software to iOS 18.6.1, but the issue remains.

Could you please provide me with a solution?