Attribute animation with animate not working in codepen, jsfiddle?

Question

Animation

I just happened to notice that some inline svg animations don't work in sandboxes.
For example, tyts and tyts - animation of the contour "mund" - "mouth" in a simple way) - At the same time, it is normal in any html environment, both locally and on any server, well, for example , here or here .
Just wondering why that is.

Answer 1

Sandboxes have nothing to do with it, you just copied-pasted the original "d" attributes of elements with id="mund" incorrectly.