I wonder if you horse is like mine - when he has significant time off (as it would be with any horse) and isn't ridden in awhile, he tends to drag his feet. He will knock every log I cross and drag his toes over every stick on the ground until I spend a couple of weeks riding him regularly. His foxtrot is also very close to the ground - his entire way of going is very close to the ground - he is not one of those high stepping types so every spring when I start riding him regularly again, we go thru a couple of weeks of bulldozing our way thru trails instead of stepping lightly. But then he gets going again and we are good to go until he goes on vacation next time...
It might just be that some hours on the trail are all that is needed.
Clippityclop is finally getting to spend some time in the saddle!