Convert old placeholder text to regular text captions?

I have six text captions on a page that were originally linked to a master slide, with placeholder object text. I have since switched master slides, and even deleted the placeholder objects on the older master slide.

I don't want this text to be placeholder object text anymore, but I want to keep the text that's in it, and it's size/positioning. Is there a way to not have Captivate see these as placeholder objects anymore?

The only thing I could think of is I have to re-create them from scratch as regular text captions. That would be a huge pain though, especially considering the size/positioning I have across five mobile break points. That's a 120 property fields! Top/left/height/width, times 6 captions, times 5 break points.

If you're asking yourself why I would want to do this, it's because I need to take these six captions and create three groups of two text fields each. You can't group text that was once placeholder text for some reason.