The following does not render how I would expect:
note over Aactivate A
The activation line starts *before* the note. If that behaviour was desired I would reverse the order of the items. Expected behaviour?
(--------)
Hello,
You can use a dummy hidden line like this:
@startumlBob -> Alice : hellonote over Alice: aaaaaaaaaaaaaAlice -[hidden]-> :Activate Alice@enduml