Say there are four modules on a page in the content pane, 1-2-3-4 stacked vertically.
Delete the top one and when the page refreshes, now all of a sudden, the module that was previously at 3 in the above stack is at 1 in the new 1-2-3 stack.
Scenario: This is a migration from an old skin to a new one, and the modules were once upon a time in "righttoppane" in a different skin. That pane doesn't exist in the new skin.
So I suppose that has something to do with this and makes it a bit less mysterious than it seems.
But a similiar situation in two modules that were created on one page and then told to "appear on all pages" ... these do appear on all pages in the correct "leftpane" which exists in the skin on each page ...
Go into Settings for the top one and update it to change the title or tell it not to display container, and save ... when the page refreshes now the other module has become the top module in the pane.
Whazzup widdat? DNN 4.8.4