Case 580L Forward & Reverse issue

I have a 580L with 2200 hrs on it. I bought it in 99 with 1000 hrs on it. Been working great till last 4 months. After starting it, I have no FWD or REV action for a few minutes till it seems to warm up. ( This started when it was well below 32 degrees, however I keep it plugged in with heat pad on Hyd tank) I had it in to the CAse dealer here last month. They drained out all the fluids and changed filters. Seemed to work fine the day I picked it up. So I started it yesterday, and same thing. no movement with shuttle in either position. It was a warm day, maybe 70 degrees. I reved it up a couple times and it started moving Fwd as it was in that position. Once it moves, there seems to be no issue until the next time I start it. I use it incidentally to move snow or a little dirt sometimes. Just my around the property machine. Anyone else have this issue? Thanks.