Take the shadowtest branch of the sponzatestapp: https://git.qt.io/laagocs/sponzatestapp/-/tree/shadowtest

Here the sphere moving around together with the orange PointLight above it generates strange shadow behavior: in certain positions the shadow is as expected. Elsewhere, near the "corners" the shadow starts fading out, eventually disappearing completely.

This may or may not be the same as QTBUG-102023