Rectangle Light Uneven

Hi team,

I am currently doing some rendering using the rectangular Light tool. I have been using two different computers and have noticed a difference in rendering.

As you can see below, there are two similar images where the light is in the same location.

I am noticing that in one, the light is diffusing smoothly whereas the other, a curve is appearing. The only difference I can see is that in the curve one, there is a note saying "Using optimised intersection kernels). However, I am unsure if this is a cause and I cannot find anything relating to this. If I had missed this, please kindly redirect me.

As always, thanks for your help in advance.

@Media_Sarsfield pls send the file for inspection, it’s impossible to debug this without a file that shows the issue. You can send the file here

@Media_Sarsfield thanks for sending the file

I suspect that this will help:
Set the falloff of the light to inverse square, and change the intensity to 3000 to start with:

btw: your side tables are floating