How to properly do {hidden} on a timing diagram in version 1.2020.09

Question

Hi,

When using the latest beta, the following example renders the desired result;

Correct result (1.2020.20beta4 / graphviz version 2.38.0) 

With 1.2020.09 / dot graphviz version 2.44.1 The result looks quite different. "{hidden}" is taken literally so it becomes a state.

Is it possible to get the desired result without using plantuml beta version?

expected vs unexpected:

Expected
Unexpected

Source Code:

@startuml
skinparam DefaultFontName Courier 10 Pitch

scale 1000 as 200 pixels
robust "Profile" as PF
PF has highest,high,medium,low,lowest

@0 as :start
@999 as :linear_end

@:start
PF is highest
@:start+1
PF is {hidden}
@:linear_end-2
PF is lowest
@:linear_end-1
PF is {hidden}

PF@:start  -> PF@:linear_end-1
@enduml

I'd appreciate to learn whether this is a known bug in the previous version which is taken care of, and if there is a workaround for the version that leads to the bug described.

Thanks