Both my M9's exhibit the same trait, steering wheel spinner winds up in a different position each time but that is a characteristic of the orbital gearmotor that drives the hydrostatic steering linkage and it my case, the orbital gearmotor is slowly taking a crap and like I said, it's really not rebuildable, just replaceable so I'll wait until it craps out and replace it. Both my M9's have always had somewhat vague steering and again, it's is inherent with the system for steering they both have. I ignore it. If it was direct connected via hard linkage, that would never occur. it's not. At first I thought I had a pinhole leak in the return hard line that feeds the hydraulic pump (and Kubota had a recall / replacement on that part sometime ago, but neither of mine have a pinhole leak (which would allow air to get in the system and cause a whine. My whine is under the dash where the hydraulic gearmotor is. Like I said, I ignore it and I check all my fluid levels prior to starting them up anyway and I do that every time and I don't use UDT nor SUDT in either of them, I use Chevron All Weather THC synthetic fluid which is actually more expensive than SUDT or SUDT2 is at the dealer but the cold weather flowability is superior to the OEM fluid, plus it's dyed orange so it's easier to see on the dipsticks. I use my can M9 in the winter and it gets COLD here and both tractors are stored in an unheated barn with no electrical service so it's imperative that the fluid I use flows well in cold weather and the Chevron does.
When it dies, I'll replace it. My units are both years out of warranty anyway,