Hey everyone!

Something weird just happened with one of my breedings and I'm losing my mind trying to figure it out

I bred two fully genetically tested Vulnyx:
Mother Rainpaw : Gene Two (NA) Tuxedo carried, nothing else
Father Graypout : Mutation Two (GI) Spines visible, nothing else

The baby here ended up with:
Gene Two (NA) Tuxedo carried: I get it, from mom, quite happy the baby inherited the trait!
Mutation Two (NI) Flower Adornment carried: what?

No parent has Flower Adornment, not even as a carried hidden trait. The father has Spines so I thought the baby would end up with a carried Spines variant, not Flower Adornment!!!
Is this a spontaneous mutation? I thought that wasn't a thing in Sylestia, but I'm new so maybe I'm missing something about how the genetics work?

Thanks if you have any answer, I'm not unhappy with this surprise but I would like to understand what happened