Can you provide the exact version of InRoads you are using and perhaps a dataset (DGN, XIN, SDB)?
With the style lock on it should use the style assigned to each structure. And this is based on the style that was assigned to the structure when it was created. Each structure has the styles assigned when it is created and is stored in the SDB, so it doesn't pull from the current/active setting in the structures.dat file. You can do an edit/review for each structure and check the 'Styles' tab to see what is assigned and what should be used. We should also look at the level manager to see if there are any level overrides, etc. in the file which could cause the line style to revert to something different.
With the style lock on it should use the style assigned to each structure. And this is based on the style that was assigned to the structure when it was created. Each structure has the styles assigned when it is created and is stored in the SDB, so it doesn't pull from the current/active setting in the structures.dat file. You can do an edit/review for each structure and check the 'Styles' tab to see what is assigned and what should be used. We should also look at the level manager to see if there are any level overrides, etc. in the file which could cause the line style to revert to something different.