I have checked my saved file, and the problem is duplicable.
Based on the two games I mentioned above, DE 602 is not firing, with AI=100%, in September 1940 with Paris being occupied at the conclusion of the Axis turn.
I believe France surrenders as result of Nation Morale being <=0 at that time.
France had a NM 0f 8,000+ before the Axis turn.
There are 3 scripts that will fire affecting France NM.
They are: -5,000 for Occupy Paris, -5,000 for AI Helper for Occupy Paris, -1,000(?) for no UK unit within 3 of Paris for a total of -11,000(?).
Making a total of -3,000 NM, or 0 as it probably the lowest possible value.
In the games, all French Forces in France, North Africa, Syria are gone, Mentioned places are Axis controlled, DE602 is waiting for Allies to occupy Algiers.
Hope this helps.