Looking into this issue myself.
Gov
I also took mine to a dealership that didn't touch it for a month, so I picked it up and took it to a JD dealer that mainly services logging equipment.
The JD mechanic "thought" it was the pump, since I couldn't raise the boom while using the mulcher, and that I didn't have much mulcher power (stalling easily, long recovery, slows down as soon as I touch material)
I have a pump ready to install, but I've been putting it off since I could still do a lot of brush jobs and kept busy with those jobs. I just busted a track so I may use the couple day wait and holiday weekend, to do some needed maintenance, like this pump.
BUT First I'm going to order the Stucchi couplers to see if there's a difference. I kept seeing that they help with flow leaking inside the coupler manifold. If a miracle occurs and I discover a fix before putting the new pump in, I'll just sell it for loss or keep it in the shelf as long as I have the machine.
I'll try to post an update this week or next after I've done these things; if it helps me or anyone else.
*note my arms also have some leak down. It will always slowly leak down but when it's hot it will leak faster and while the engine is running too. It's not so much continuous movement as it leaks down, as much as it is "popping" as it goes down.