John Deer riding mower anti-scalp wheel failure

I have a JD X320 with a 48 inch deck with rotatable anti-scalp wheels.

The left front anti-scalp wheel keeps failing. Basically, friction is causing the wheel the hub to melt and the wheel collapses.

I have been through 3 wheels and one spindle and the problem persists. All the wheel spindles are set to the same height, and the cut itself seems level to me.

I don't know if it should be, but when the deck is in the lifted position, the back is higher than the front, so the front touches down first when the deck is lowered to cutting position; but only the left side wheel fails.

I would guess that that corner of the deck must be warped downward somehow and is causing that particular wheel to become unevenly over-loaded. How can I check? Or is there some tr explanation, or an adjustment workaround?

Thanks.

although it is plastic lube it either with rubber grease or with Tri-Lube ( from a push bike shop. )
Some like graphite powder