Try these three ideas. 1)Very good chance that one of your hose lines to the unload cylinder has a collapsed inner lining. This only affects flow when the oil is hot and makes the inner lining soft. I've seen this before on a bale thrower. 2)As weird as this sounds, check your valve stack to see if your cellinoids are releasing back and forth properly. 3)I had trouble with my auger not swing back into its cradle after about 30 minutes in the field. My case mechanic showed me where my return sensor in the cradle was sticking and basically worn out. Replaced it and all was well.
