Much of the Front had become a war of movement prior to the Armistice. The collapse of the Russians had freed many German soldiers for an offensive in the West that spring and summer. It was stopped and the Allies began pushing back. Google "the Hundred Days".

So many of the soldiers were marching, not cowering in trenches. Combat-wise, it was still war, people were fighting and dying. Up to the last minute.

Follow up: how much did the armistice change the conditions in the trench. What was it like the day before the fighting stopped, versus the day after?

Are there and diary entries (or the like) showing the change in attitude/atmosphere?

People didn't know the armistice would hold out, so the forces who had been on the advance halted and dug in to await further developments. The terms were pretty harsh on Germany, so there was always a possibility that the truce would break down. This book indicates that the lines were static for another few days, but within a week everyone realized that the truce would hold, and started their demobilization. The Germans were to withdraw beyond the Rhine River, while the Rhineland would be occupied by the Allies. For his part, Pershing selected the occupation units, and sent the rest to the rear to build facilities to embark themselves on ships for home. The Rhineland occupation force then advanced as the Germans evacuated territory in the following weeks. The pattern was surely similar for the other allied armies.