When we moved from 4.18 to 4.19 our project, we got some strange problem: If we change parameter in material Engine start compile shaders, and that happen even if we change parameter on 1. Other problem we see - engine start compile shaders, and in viewport message show that need to compile 400000…

For resolve that problem with compile shader always just turn off Live Preview. Problem with 4kkk shaders - its not my area of responsibility =)