I have the same problem in three different computers (2 are mine, the other is from a coworker).
After the 2019 update I'm not able to render AE comps in AME because some "Slider control" expressions are not working. In AE preview everything seems to work fine, but the result after AME render is not. I'm not sure if any other property or effect works well in expressions. But for now this is what not. And is very disturbing.
I ask you to do this and test if AME render it well or not.
I've tested in a Mac and it's failing too.
I think this is a language issue. My OS is in spanish but the software is english. This has worked well always until 2018.
More info: If Ichange "Slider" to "Deslizador" AME is now processing the expression, but AE preview does not.
Copy link to clipboard
It seems that one of the latest updates has fixed the issue. Finally.