Issue with dynamic weight paint & particles

I used dynamic weight paint on this one and I can’t figure out why this plane starts emitting particles from it’s origin point at random frame.
So I placed the origin point to the left side of the plane just as a workaround to get it out of the camera view.

But would be really helpful for the future for some help why is this happening? Is it a bug?
0001-0070.mkv (200.4 KB)