A few questions for more info. I think comparing the same thing would be better here - looks like the DR render is a completed render, while the render region is still running (and a render region). So, maybe there are things that run when the render completes that haven't happened in the region - is anything like Denoising being used? Anything like Motion Blur (just as a thought due to the way the blurring looks, off the top of my head I don't think Motion Blur should be any different in a render region, but might be good to know)?
Anyway, to compare like with like, I would run a full render, no region, one with DR and one without, and see if this difference still happens. As well as checking if any "end of render" things are having an effect, it will also check that this is a DR bug and not a render region bug for example :)
Next up, if the two are still different, I would save the EXRs from the local machines by enabling the [DEBUG] retain EXRs option so you can see what each machine is calculating, and see if any are offset for any reason.
Other things to check are that the same plugins are installed on all machines, same Corona version, etc.
If the problem isn't found, and / or the EXRs show that there is some offset or blurring from one machine and not others, could you share the scene? There's the private uploader if it can't be shared publicly (
https://corona-renderer.com/upload)
EDIT - attaching where to find the retain EXRs option (its tooltip will tell you where to find the EXRs)