Mobile compiling shaders

i have problem with amount of compiling shaders when i launch my game on my mobile device. Its compiling over 5000 shaders every time and my game is very simple. Only 2 materials and only with color. When i delete DerivedDataCache folder and open my project it was compiling only 200 shaders so why when i launch it on mobile there is compiling 5000? I am new with UE4 do i have no idea is this normal or something is wrong. I am using version 4.25.