The Maplex Label Engine for ArcGIS Desktop 10.3 with the 'Never Remove (place overlapping)' setting enabled causes the labels to change orientation if they overlap.
Last Published: July 29, 2015ArcGIS for Desktop
Bug ID Number
July 16, 2015
November 24, 2020
ArcGIS for Desktop
Operating System Version
This issue was not reproducible when tested by the development team. Issues may be given this status when they cannot be reproduced or are no longer relevant in a development version of the software, but a specific fix was not installed to address the issue. The issue's Additional Information section may contain further explanation.