Seconded. This appeared to me to be happening only in the middle of the Mordor Besieged map. Near Dingarth, no trouble. Near Barad-dur, no trouble. Elsewhere, the new map didn't persist properly, though you could open it from the old map.
"No sadder words of tongue or pen are the words: 'Might have been'." -- John Greenleaf Whittier
"Do or do not. There is no try." -- Yoda
On planet Earth, there is a try.
Indeed, in a world and life full of change, the only constant is human nature (A is A, after all :P).
We old vets need to keep in mind those who come after us.