The 'Stay Tuned' animation was created in After Effects and rendered in Premiere Pro.
It wil be a streaming issue and nothing to do with your movie.
Try viewing it with HD turned off.
Right, as I note, the file itself has flawless motion. And curioulsy, HD usually improves it.
I'm just wondering if in the wide array of file types and render settings there's not a selection that would result in flawless youtube performance.
There is a youtube render Preset, but I've always found the quality to be lower than what I want and when I modify it, the Preset type is redefined as Custom. But maybe keeping it at the youtube Preset is the answer, and the higher quality I want is the problem. But I see higher-qualitiy videos on youtube that don't stick. ???
What size is the source footage and sequence?
1280 x 720 for both, and the source footage in the 'Stay Tuned' example is pure After Effects, no prior footage.
The better youtube performance with 720p suggests rendering to fit the 480p default might be the way to go. But I hate to cut potential quality.
Wish 720p was youtube's default if the file is 720! Probably some day not too far off.