Hm ...
How about the pens?
BTW, you really should start using View Map views instead of Project map views. View Map views are saved with settings and therefore are the same every time you open them.
The project Map view are "raw", they have no ability to save settings and so show you whatever the last settings were - regardless of why or where those settings came from.
To get a grip on this, save this view into the view map, review all the settings of the saved view and check the settings of the pens etc. This will help you with consistency.
For example if you have looked at a section and then returned to this Project Map view of the plan, you will have inherited whatever settings were current in that section.
PS add your AC version to your signature line, thanks,