Gradient Map Clipping Mask does not respect layer boundaries

Hello,
I am from Germany and I am communicating via a translator.

I used an existing calendar page as a template in order to customize it.
The top part should get a metallic effect with a Gradient Map Adjustment Layer – a bright stripe in the center that fades outward into the selected color.

The issue: when I apply the Gradient Map as a Clipping Mask, it does not behave as expected. Instead of being restricted to the layer boundaries directly below, the gradient is calculated over the entire canvas and then only displayed as a cropped portion inside the clipped object.

In other words: the Gradient Map ignores the clipped layer’s dimensions and always applies globally to the whole document. This prevents me from creating the intended metallic effect within the element’s boundaries.