Homekit limited to one scene?

Is the built in HomeKit implementation limited to one ‘scene’?

I created a Lounge_On and Lounge_Off scene that basically turns on a dimmable entity to full and three bulbs on, obviously off just turns it all off.

They appear and work as scenes under the same room.
I added them both to my homekit.yaml file but only Lounge_off appears in my home on the iPhone.

What am I doing wrong?

Ok something weird is happening…

I duplicated the working scene to Lounge_Test and it along with _Off appeared on homekit.
I then thought ha! just something odd about the existing one so I binned it, removed the code then renamed the working _Test to _On and not that’s vanished so back to how it was.

Is homekit trying to be clever and not adding Lounge_On as the room is called Lounge and On is a command although why does _Off work