I have Kubota insurance so if it's not covered under warranty I will use that.
At my Kubota dealer this would not be covered under warranty. It is operator error.
The dealers know how tightly defined warranty claims are by Kubota and all other tractor manufactures.
KTAC insurance is excellent. $250 deductible, then everything on KTAC, including transportation. I have had one claim on eachh of two tractors in seven years. KTAC is a model for how insurance should work, but usually does not. Your dealer functions as KTAC's adjuster.
Not sure if this would work, or if you have tried it. Have you put a floor jack under the side that is not locked in, and tried to lift up? That may take some of the weight off it, and may allow you to get it off the grill and allow it to settle to the ground.