I have a mapbook (Data Driven pages) derived from a strip map for a pipeline project. As it's a strip map the rotation of each page varies depending on the orientation of the pipeline feature, for each page I have a feature class of lines indicating linear intersections (roads, rail, etc.). These lines appear vertical in each rotated page and have an associated horizontal Maplex label that is set to offset to the right or left of the line, along with an associated callout arrow and line. In ArcGIS 10.2 this setting displayed as expected, but in 10.3.1 the vast majority of labels are not offset and are placed horizontally on the mid point of the line. The offending labels also don't stack even if that setting is checked.
I initially thought I may have missed a setting in my current mxd project file, but when I open an older mxd, with identical labeling, that too has the same issue and leads me to believe the issue is related to 10.3.1. Anyone else have this issue and have any workarounds?
How the labels used to display (10.2):
How they display now (10.3):