Bug with instance static mesh (max amount?)

Hello! I am working on procedural city generation, and I have parks generation in it.

So you can see I have a square and I’m filling it with grass. I generate points inside square, cycle through all these points, and if there is no collision at the point, I’m placing a grass instance. But when I generated a realy big city I noticed a bug.

I dont think that problem is in my code, I checked everything twice. Maybe there is some limit in UE for instances? (park 1 and park 2 are making instances from different instance static mesh components). Does anybody had similar problem?