I have had multiple projects where the UI seems to become "corrupt" in the designer. It always seems to pertain to split containers, DataGridViews, and anchoring the DGV inside the split container. It seems the DGV anchor somehow becomes de-synced and the DGV grows larger than the Panel that it is supposed to be anchored within. This causes a part of the DGV to be cut off and no scrollbar is available to see the rest.
Has anyone encountered this, and hopefully also found a fix?
The solution was to get rid of the split container. I started to remember other projects I've had issues with the designer also contained a split container.
I found a few bug reports about this on the Microsoft website and they appear to have been swept under the rug. I have a feeling this is a known issue that is not likely to get fixed.