Thanks for the screenshots.
The information confirms that your Intel UHD Graphics 605 runs on WDDM 2.5. That means it doesn't support Hardware-accelerated GPU scheduling, a feature introduced with WDDM 2.7.
Because of this limitation, the Bubbles screensaver shows a black background instead of the transparent effect seen on systems with full hardware acceleration. It's not a bug; it's just that the GPU doesn't support the feature required to render it transparently.
Since it's an all-in-one PC, upgrading the GPU isn't an option. So, unless Intel releases a driver update that adds support (which is unlikely for this model), the black background will remain the default behavior.
Feel free to ask back any questions.