You don’t explain much what’s going on or what you’re trying to get it to do instead, but let me take a wild guess and you can tell me if what I’m saying is correct:

• You’re trying to print two separate items.
• The first layer of each of the items in question happens to be a rectangle roughly half as big as what appears to be a single rectangle in the picture provided.
• But you had the two items separated by a small amount in the CAD software and/or slicer.
• You’re wanting it to print two separate items with enough margin in between that they don’t merge into one single inseperable item.
• But somehow it’s fusing them.

Is that roughly correct?

If so, my first guess as to what might have caused that is “first layer expansion”. Your nozzle is too close to the bed, making the width of the bead it lays down on the bed spread out a bit more than it should, resulting in a wider bead than you’re trying to make. And the amount of space you left between the two items is small enough that the first layer expansion is pretty much entirely swallowing up that margin. To fix, increase your z-offset a bit. If the first layer expansion isn’t an issue otherwise, you could also “work around” the issue just by separating the items by a greater amount in your CAD and/or slicer software.

If more than just the first few layers remain fused (like, if the parts hypothetically had straight vertical sides and every layer fused all the way up, rather than just being fused on the first 1-to-6-ish layers), then it’s probably something else. Maybe overextrusion?

And, again, both of those theories are contingent on whether I’m even interpreting the question you’re asking correctly.