Problem:
In the custom line style selection tool, the annotation scale setting must be set to "Full Size 1=1" in order to view the custom line style in the preview window.
At a scale of 1/2"=1' (1"=2') or above, the line style displays as a solid line.
This behavior is also observed in the custom line style editor tool.
See the attached video for further details.
Idea:
Modify the custom line style preview window to always display custom line styles based on "Full Size 1=1", rather than rescaling based on the annotation scale factor.
Note:
This issue was submitted to Bentley tech support and determined to be "working as intended" rather than a bug.