Currently linked models display their own line weights regardless of "By Host/Link" status.
Recommendation:
VV > Revit Links > Display Setting =
- By Host View = displays host model's line weights.
- By Linked View = displays linked model's line weights.
- Custom > Basics : Object styles = <By host model> = displays host model's line weights.
- Custom > Basics : Object styles = <By linked model> = displays linked model's line weights.