I'm curious, is this a mutation or something else? This is a store bought Roma plant so I do not know the genetics. The tomato fell off whilst I was collecting my harvest around 8/8/22. It didn't take much for the tomato to pop off the vine. It looks like two Roma tomatoes stacked on top of one another. Other people have said it is a single Roma tomato with a very tight waistband. I have not attempted to pull them apart because I am waiting to see how this ripens. I've been growing tomatoes for 23 years and I have never see an abnormality like this.
FWIW: Zone 6a