Cache Uniform Expressions Lowering FPS to 5 in 4.19

Hello everyone! I got a big problem in 4.19, maybe you guys can lead me to the right direction!

At top, is the 4.18 project and the bottom one is the same one as 4.19(edited)


You see, the material at 4.18 (despite the number of the same material) has literally no issues with fps.

But only one flipbook with that material below at 4.19 is going insane.
It seems to be the result of “Cache Uniform Expressions”.

What does it mean? Why does it Cache so much? Is there any way to prevent this? Thanks in advance!