Wow! That is interesting. If you did not see them at all that would be one thing, but they flicker in and out. A few questions:
For example, I use AI files. If I zoom inside CH, it zooms before converting to pixels. If you zoom in Prem Pro or AE then it pixelizes before sending them the video, so scaling afterwards can create problems. An easy solution might be to change where you are zooming (which does not explain the bug, but might work around it).
The reason I was asking about the cycle layers on visemes is to work out whether the issue is with the last frame of the cycle. It is strange something appears and disappears. The other cause is something appears in front. But if it works without render as vector then that is just a bit weird. (I have never used render as vector to be honest.)
I've done some digging.
The mouths that disappear were all done in .AI and colored using live paint.
The ones that remain were just one solid line (neutral mouth) or solid circle (w-oo)
So what I just did was make a new test mouth layer without using live paint and it appeared. So I can go back and make new mouths for all missing mouths.
But... when I clicked on render as vendor one of the giraffe spots that was a lesser opacity suddenly turned to its regular color. Can't seem to win here.
I don't know why using live paint would have such a reaction.
Also, as to your question. I am zooming in Character Animator. The character starts on screen around 65% and moves to 120%. But the mouth is pixelating at all times
My gut reaction is if the file is an Illustrator file, and you have used a vector line for say the mouth and it is pixelizing, then "render as vector" probably won't help. (I could be wrong, but something else sounds funny.) I use vectors in Illustrator and zoom like 500% without problem. So curious. (If you drop bitmap images into an Illustrator file, of course they will still pixelate when scaled.)
Could you provide a screenshot of the pixelization? E.g.PrintScreen to get a screen grab and upload that (rather than a photo with a separate camera).
I think Illustrator files have "document properties" that talk about resolution there... hmm, cannot find it. Just curious what it said.
What resolution is your scene? If the scene is lower resolution than your monitor, you might see pixelization due to that maybe.