Yup. 5.5.4 and still here 
However… after further investigation, I don’t think this is a bug.
This issue happens both for text and image. When you look closely, it looks like that widget is getting scaled inconsistently, a little bit in X and then in Y, then X and Y again over time. It also seems to be readjusted for its anchor.
That makes perfect sense to me. You can’t scale something by 0.1 pixel or half of a pixel. You can only scale it by 1 pixel minimum.
So now imagine that your text(or image) has 500pixels width and 250 pixels height.
When you scale both axis using the animation and scale, it uses value 1 as default - 1 means its original size.
Now, as your scaling animation follows, it will increase the scale a little bit every frame.
So first frame, your scale is 1
Second frame, your scale is 1.002 for example(check the values, after the comma, they are really small).
This means that at the first frame, your image has size of:
Width: 500px * 1 = 500px
Height: 250px * 1 = 250px
however, at the second frame, the sizing looks like that:
Width: 500px * 1.002 = 501px - this is good, the width grew by 1 px
Height: 250px * 1.002 = 250.5px - this is the problem - we can’t have half of the pixel rendered on the screen, so Unreal will likely keep it as 250px.
In this situation you can see, that your image or text will now slightly loose the aspect ratio and be 501x250, where originally it was 500x250.
Now, if you forward by another frame, your size will be 502x251, next frame 503x251(because 251.5 is not possible). As you can see you will have one frame where X scales, and then another frame that both scale.
This issue is even worse, because scaling in animation will be like 1.00001, 1.00002 etc. In addition to that, I presented example where your image/text is perfectly twice as wide as it is tall, but imagine that your text is like 347x123. This complicates it even more and you can easily end up having 3 frames of X scaling and 1 frame of Y scaling, and that is very noticeable.
To make this matter worse, the anchors are also coming into play.
Imagine your image/text is centered in X and Y. Well, if its width is odd number, like 55 for example, it’s not a problem, because it can be placed in the middle, but as you scale, the width will grow from 55 to 56, in which case the image has to be placed either 1px to the left or right, and then 57 and it’s back in the middle. So this effect adds to the overall feeling of this stuff being “choppy”
I hope people have some clarification for the future.
