Blend Material Causes FPS Crop!

Hello there. I encountered this problem in Unreal 4.24 version. I thought this issue was related to the Unreal version. So I waited for version 4.25. But I had the same problem in the tests I did yesterday. When I create Blend Material with the addition of Megasceans while buying 120 FPS, it decreases up to 15-20 FPS. I think there is a major problem with this issue.