Describe the bug
Expect the bar to not produce a smooth progress animation when it first shows

Do you have an error log of what happened?
As you can see in this video the sky golem mount cast bar has a smooth progress animation applied to it. When the bar is shown the previous progress is used to start the smooth progress animation even though the bar was untriggered. The expected behaviour would have the bar's not progress smoothly when it is first shown.

To Reproduce
Have a bar hide when it's progress is some value, then show it when the progress is smaller than the value it was hidden at.

Screenshots
https://www.twitch.tv/videos/388360542?t=28s

This is fixed for the next release.