In WW2, France surrendered immediately when the Nazis were about to take Paris, but in the Hundred Years War continued to fight even as the English besieged Orleans. What was going on there?
The Hundred years War was actually a series of conflicts over 116 years that historians have lumped together.
Also our concepts of nations as well as states and what it means for two states to be at war have changed. For example; a lord from English territories may be in active combat with a duke from French holdings and this conflict may not grow into the two larger states fighting.
Lets also not forget the 400 years between the two conflicts. A lot can change in a country in that time.