Thanks. One other place to look would be to see if you got any errors or warnings when importing from DICOM. You can see an error log by clicking on the “X” in the lower right of the Slicer window (which is red if there are any new messages there since the last time you opened it).
I agree this shouldn’t be happening. My guess is that there is something which is either incorrect, inconsistent, or incorrectly interpreted by Slicer in the DICOM headers for this image volume.
Your problem is not the same, but there might be some helpful related info in this thread: https://discourse.slicer.org/t/the-slice-view-is-of-different-intensity-than-the-actual-object/