This is one of the complaints about the RTVs. I have an X1140. On the X series I know that the brake also engages a pressure relief valve on the HST to help with shifting. I believe this model had a knob on the dash that relieves the pressure. While mine sifts fine normally, when the system is under load, like on an incline, it occasionally can be difficult to get out of gear. Disengaging four wheel drive can be difficult on an incline as well. When this happens I usually just bump the throttle and hit the brake immediately and sift to Neutral then I select the gear. If it doesn't want to go into the new gear I release the brake a little and it shifts into gear. It has worked every time on my machine though usually it shifts fairly smoothly. Kubota says they made changes in the newest two models to make shifting easier. I really don't have issues with mine going into gear very often but when I do I am usually on an incline. The WORST thing you can do is force it into gear. That is how the shifter jumps inside the housing. The other terrible thing to do with these machines is shift gears or engage/disengage four wheel drive while driving. Both should be done when stopped. I commented on your Facebook post in the RTV groups but will mention it here as well. On an RTV with hydraulic bed lift, you can put the bed in Float mode by pushing the handle all the way down. On mine you can tell when you have pushed it into float. It will not go down any further and it will stay down. Then you can lift the bed up manually if you cannot start it to get to the engine and transmission. Not sure about the earlier models but on the X series like my X1140 there is a safety bar located under the bed you put on the hydraulic cylinder to keep the bed up. Sorry for a long reply, hopefully some of it is useful if you work on more of these machines. They really are work horses but they have their unique attributes. Kubota RTVs are more like tractors and less like typical side by sides.

Spot on. Gets stuck on an incline and then has to be fixed… seems like a common issue with these. Thanks for the video!

Some have a hydro relief valve that activated when you pull the choke style button beside the key, others have a hydraulic relief valve that relieves pressure when you put your foot on the brake at a complete stop. And you should shift the shifter like You would a four-speed shifter because they are known to get jammed locked in a gear if you go from reverse to medium or low to high in a u instead of straight up and down pattern

Mine has what looks like a choke cable knob on the dash. It must be pulled out to shift the transmission. I believe it some sort of a bypass that releases hydraulic pressure.

Were you holding the foot brake down? I think there’s an interlock. It needs to be stopped, and the brake depressed to go from reverse to forward in an incline.

I also have an RTV 900 XT. It soon became difficult to get it in to reverse. Now it's impossible to get it into reverse. If you manage to get it engaged it feels like forward low. The low gear is now also becoming difficult to engage.