On recent Slicer preview versions, the module panel automatically resizes based on the size of the contents. This is an understandable design decision. As someone who often is switching between modules, I personally would prefer that the slice views not be changing sizes as I do so, but there are advantages either way and I can live with it as it is now.
However, there is one case where I think the auto-resizing is both very annoying and potentially functionally problematic, and that is when mousing over the slice views causes the Data Probe module to change dimensions. This causes a resizing of slice views, which causes the point under the mouse to change, which causes a change in the Data Probe data to change. If I position my mouse cursor near the edge of the image volume in the slice view, I can get into a state where the shift gets into an endless loop where one state is “Out of Frame”, which increases the size of the Data Probe module and causes a shrinkage of the slice view, which puts my (non-moving) cursor inside the frame of the slice view, which decreases the size of the Data Probe, which expands the slice view, which puts the cursor outside the frame, etc. This case is a vivid illustration of why this is a problem, as just putting my mouse cursor in one location should not possibly lead to an oscillation in the partition sizes.
The obvious solution for this is to not allow the Data Probe to trigger resizing of the side panel, instead it must use whatever space is available.
If you are having trouble reproducing, I can record a video and share it. The problem can be generated near the edges of displayed segments as well as near the edge of the volume, so it is not sufficient to catch the “Out of Frame” case.