I recently updated to Unity 2018.2.0f2. My game generates levels procedurally, and I noticed that this process was taking significantly longer than it did in my previous build, which was using Unity 2017.2.1p4. I narrowed down the issue to a line in my code where a BoxCollider2D's size was being changed. This line is run a very large number of times in rapid succession, but in Unity 2017 this did not cause any sort of performance issue. Is there any sort of new setting in Unity 2018 that I might have missed that could be causing this? Any other ideas? Or is it maybe time to write a bug report?