No resources to work on this at the moment; Can be worked around by using 540 rotation instead of 180
If a static mesh is rotated 180 degrees, it is made slightly smaller than it usually is. There are some other degrees that can give the same effect without the shrinking, such as 540.
This also occurred in 4.13, as far back as 4.11
Head over to the existing Questions & Answers thread and let us know what's up.