QML, WMF: Single color rendered across VideoOutput geometry

Video playback sometimes seems to render only a 1x1 portion of the video across the whole Video Output (QML) area when playing videos through QtMultimedia on Windows Media Foundation.

These issues appear with all types of tested media (MP4, AVI) but not deterministically in every run.
If this issue occurs, it does instantly (after setting VideoOutput visible=true) until playback of the media stops.

Attached: 2 screen casts of playing back the same video, one with and one without rendering issues

DirectShow is not an option as we would require K-Lite which causes serious stability issues (ffmpeg decoder causing crashes on close, etc)