This also affects video pop-ups triggered by Opera extensions, including embedded or promotional videos, or a booking demo inside a website or extension, the pop-out may turn black or fail to appear entirely if GPU acceleration is not truly working. Simply enabling or disabling the setting in Opera’s system preferences is often not enough. Users should check opera://gpu and confirm that video decode and compositing are listed as hardware accelerated; if they show “software only” or “unavailable,” then PiP will not function correctly.

Updating GPU drivers directly from NVIDIA, AMD, or Intel, resetting GPU-related flags in opera://flags, and restarting the browser can fix the problem for many users. However, for some Windows systems, the issue still persists even on recent Opera versions, indicating an unresolved regression in Opera itself rather than user error. In those cases, using Opera GX or another Chromium-based browser remains the most reliable workaround, especially if you regularly rely on pop-out videos

In my case, it was disabled, and after enabling it and restarting the browser, the Picture-in-Picture feature started working again. My Opera version is 114.0.5282.185