Hi Paul,
Please be aware If we are using Shape Symbology to represent directional arrows, we have a couple bugs related to Shape Markers display and placement when generating Vector Tile Layers/packages.
BUG-000121173 : Angle alignment for the point symbols are not honored in a vector tile package in ArcGIS Pro.
BUG-000119467 : ArcGIS Pro incorrectly displays the shape marker symbology in vector tile packages when used in a line layer
The bugs here are likely the cause not having one to one results form the input map.
If you're running into this problem please try to convert the Shape Symbols in your map to Features with the Feature Outline Masks tool.
Also feel free to contact Esri Technical Support if you're still experiencing the issue or if you would like to have your account attached to bug records that are submitted.
I hope this helps!
-Adam