Epic has slowly been improving their includes to more closely follow Include-What-You-Use and doing fewer broad includes. They could also have changed something so that a header you were including no longer needs it so you don’t get it for free.
You’re just missing a MathUtil.h include somewhere.
There are the release notes, but they won’t go into the level of detail needed to identify this sort of thing. And it would be unusable if it did.