Landscape painting lag/delay


I have a shader using landscape-blending to blend 7 materials using height-masks. The material also uses height-based tessellation. Lately when i paint on my landscape Unreal Engine freezes for 1-2 seconds when I release the “paint-button”. I have checked my computer performance during the lag-spikes and it does not seem to be a performance issue. No “performance spikes” when the error occurs. It would not be a problem except that I have to paint a very large landscape. Those seconds will add up. Does anyone have a solution?

Tried on a smaller square landscape and did not have this problem.


Updated to 4.7.4 today and the problem is gone!

I’m using 4.13 and the problem appeared. Any idea what is causing it?
Similarly, after painting or sculpting the terrain, UE lags for 1-2 second the moment i release my mouse.

the problem appeared to be back in 4.19.1! why does that happen?