Okay paint from reference gurus. I need help

I was really hoping to find more people talking about this new change ! :( Did they change it so that ALL custom paintings are flagged as custom content? Or just paintings of CC artwork?

I wanted to cheat up Bella Goth's painting skill and have her "paint from reference" a bunch of pictures of Mortimer Goth and her kids, and decorate the renovated mansion I made for her and upload it to the gallery. I was going to make it look like she had paintings from Forgotten Hollow, Glimmerbrook and Strangerville, as well as Willow Creek.

It's a base game renovation and I wanted to make up some fun storylines with the custom paintings!