The use of hide empty descriptions removes inline style in State Diagram.
hide empty description
state "Dashed 1" as State_1 ##[dashed]
State_1 : description
state "Dashed 2" as State_2 ##[dashed]
Produces one box dashed, while the second one is not. If you remove "hide empty description" both are rendered dashed.
I used PlantUML 1.2021.01.