Strange occurance

Zwift changed my novanta session to a just ride where I was to go a minute with 5 out of 10 effort, a little rest then again at 6 out of 10 and so on. It then just left me in a normal just ride session. I can’t find anywhere why it did this or it happening to anyone else.

Can anyone explain this?
I’ve attached a picture of my result.
You can see it’s the normal novanta at the start, then there’s 1 minute ramp ups. The rest is freestyle.