How to allow 'Hey Google' on a locked screen? (but really)

I have a Samsung Galaxy 25+ running Android 15. I used to use 'Hey Google' (I do not know how this is properly called) with unlocked and locked screens on this and previous phones. After "something" (Android upgrade? switch to Gemini?) **I cannot have Google Assistant answer when the screen is locked anymore**. The answer from the phone is (more or less, I use the French version) *"I can do that but first you will need to unlock your phone"*. I went through all the settings, the voice match procedure (twice) and I have enabled on the phone everything that is required This screenshot shows that the Assistant can access personal data This one states that the functionalities of Google Assistant are available on the locked device It states that in order to gain access to the Assistant when it is locked (yes, I do not understand either), I must match my voice and enable *Hey Google*. Which is the case: So WTF is missing?? The settings are super difficult to find, I manage to get to them via some weird searches but never step by step. There may be something else I need to enable that I did not find - but where?