How to keep widget Fill after rotation?

I have a widget (an Image) inside a Vertical Box, and its Size is set to Fill.

When the widget is not transformed, it fills the available space as expected. However, after applying a Render Transform rotation (90°), the Fill behavior no longer works—the widget no longer fills the container.

It seems that the Fill property only works correctly when no Render Transform is applied.

Is there a way to keep the widget filling its parent container even after rotation?

Any suggestions or workarounds would be appreciated.

Best bet would probably be to make a material and rotate the texture UVs