Units Gaining Fatigue - Why?

[Engelbrekt]

I´m playing Market Garden Alt campaign in a PBEM. It is night, some of my Allied airborne units are Digging-In, others are resting. Now it seems many units are gaining fatigue when they should be recovering fatigue. They are doing nothing, no activity and no fire against them or at the enemy.

Many, if not all, of the units in question were Digging-In the previous turn but I removed that status from them to rest them this turn. Still they have gained fatigue. I understand the rules that switching on or off a command does not affect the unit in the next turn? What am I missing?

//Engelbrekt