Did anyone solved superslow shaders compiling ? & material editor freezing ?

By using latest ue4.22 there is insane slow shaders compling times and freezes.

For example if I change something in my landscape material and apply , it compiles 1200 shaders !! omg

Then when I am gonna paint new layer on it it compiles 1200 shaders again and again… what is it ? Maybe some bug in ue4 ? When I change engine scalability from HIGH to MEDIUM it want to recompile 13000 shaders again omg . Hitting save material sometimes freezes for 1-5 minutes or getting stuck on 50%