Cannot start a custom-named pssdiag service using the /A parameter

[PiJoCoder]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?
Cannot start a custom pssdiag service using
pssdiag.ps1 START /A "pssdiag1"

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem **

powershell -File pssdiag.ps1 -R -A "pssdiag_joe"

powershell -File pssdiag.ps1 start -A "pssdiag_joe"

Error:
C:\temp\pssd\pssdiag.ps1 : Parameter set cannot be resolved using the specified named parameters.
+ CategoryInfo : InvalidArgument: (:) [pssdiag.ps1], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : AmbiguousParameterSet,pssdiag.ps1

What is the expected behavior?
To be able to run the second command above

Which versions of SQL Server and which OS are affected by this issue? Did this work in previous versions of our procedures?