Playback error in 1/2 resolution, when my video is scaled above 100% in width

Hi there,

Lately I have been editing my clips, among whose some are portrait - so I need to scale them to fit in my landscape canvas. However, when I scaled it above 100%, the playback becomes glitchy.

I have unchecked the “proportional scaling” box, and under this setting the playback also failed to work.

When I change the width proportion to under 100%, things got back to normal, regardless whether the (width/height) is below 1 or the height is above 100%.

The video was recorded in 4K resolution 30fps, with a colour space of Rec. 2100 HLG, 4:2:0 HEVC 10 bit. No alpha, no LUT, and square pixels.

Nothing wrong appeared on my compatibility report, regarding to this video clip. This error happened to every portrait video whose original width is lower than the width of the project canvas.

I am using a Chinese interface so forgive me that I may not name the entries of the UI right in English, but this is really bothering me (too much “silver linings”). Please check this out - I’d be happy to provide you guys with more info.