I had a similar problem, losing the float at 10 hrs, and lifting the font of the tractor if I tried to use it. The dealer came out, removed the end cap off the lift spool, tightened up the end of the spool which had come loose. The bolt? on the end of the spool had loosened off and extended out so that the lever could not push the spool forward enough to engage the float. It was hitting on the the end of the cover.
My spool cover is held on by 2 4mm hex key bolts. A 7/32 will work, but can slip when tightening. Remove the 2 bolts, the cover will come free, be careful not to drop anything. Check inside the cap, you'll see a metal ring inside a groove, that's the detent. Make sure that it is intact and moves freely in the groove.Check the bolt? on the end of the spool to ensure that it is tight as well. 4mm again I think.
The bolts are on tight, a little penetrating will help.
I added a couple pictures showing the valve body and the end of the spool. You can see the paint chipped off the lift spool cover.
It also could just be dirt inside the cover stopping things from moving.
Get rid of any hydraulic pressure before doing any work!