Problem displaying video with alpha channel not clearing between frames

We want to display a video with alpha channel like this one (https://examples.phaser.io/assets/video/alpha-webm.webm). We built this Sandcastle on which we changed the video source and the material transparency property.

The problem is, as you can see, that the frames are stacking even if you pause the video (with the cesium controllers, if you activate clock synchronization).

Is there a way to solve this problem, or an alternative way for displaying videos with transparency?

Thanks in advance!

Hello,

Thanks for reporting this! This looks like a bug. I filed a bug report on our github here: https://github.com/AnalyticalGraphicsInc/cesium/issues/4935

I posted a link to this forum post so we can let you know when we are able to look into the problem.

Best,

Hannah