Wrong blending of normal maps

Hello! I have a strange problem with a blending of normal maps after updating my UE4. I have two normal maps that look good individually. Here is the first normal map, and it is the same on the model.

108293-waterbigw1_nm.jpg

Here is the second normal map, and it is also on the model.

Here shader structure.

I continue to answer, because investments are not fit
And so it looks the result of mixing the two normal maps.

I made a test file in an graphic editor, in this file I blend by overlay well as two of the same normal maps.

I made the same number of tile, which I made in the shader by texture coordinate node. The result is as good as it should be.

What did I do wrong when blending the two normal maps in a shader?

Can you try to use this setup instead of the BlendOverlay node? P.S. the BaseNormalMap and DetailNormalMap should be textures

Hello! Thanks for the answer! I made a shader as you recommended, everything works fine. Here are the results

108417-rockpropershader.jpg