Looks that deactivate doesn't work when teoz is enabled:
!pragma teoz true
b -> a ++ #red : hello
b -> b : self
Interestingly, when running plantuml locally with teoz enabled, png seems to be generated correctly (like in first picture) but svg has result like in second picture. Generated svg has source where "deactivate" is correctly generated.
Tested with PlantUML version 1.2021.2, initially noticed with version 1.2021.00