The Compare tool is intended to show the first version and the twenty latest versions of the object. In this case however you get the twenty first versions. This is because the Compare tool uses the change numbers of the object to figure out the sorting, but the change number with MorphX version control is always 0.
To fix this, make the following change to \Classes\SysTreenodeCompareContext\comparableListTreenode, lines 110-111:
while select item order by ChangeNumber desc, Version ascwith
while select item order by ChangeNumber desc, Version descThis is obviously just a quick fix, but will work as intended until Microsoft fixes the bug.