I guess you are referring to the 'Drôle de guerre', the time between the defeat of Poland, and the beginning of the invasion of Denmark and Norway. During that time, while there were some small battles at sea, the border between Germany and France was next to peaceful, i. e. no border skirmishes except for a very few at the border of the Saarland (IIRC), no bombarding of enemy troops by artillery/aircraft, even no true attempt to sink freight barges on the Rhine.
During that time, quite some people thought that the war was actually evolving into an 'armed peace', combined with economical warfare, where France and UK were trying to pressure/starve Germany into an armistice by cutting off maritime trade, while the Germans were trying the same, whilst building an Eastern Europe Empire.
There were numerous rumours of secret negotiations between the Allies and Germany, and the will to fight against Germany seemed to slowly dwindle with the Allies.