Sorry to hear about that. I've found small squares of stall mats are good to prevent sinking and sliding which can lead to leaning. Still, my TC is relatively stable even with only 3 jacks touching the ground. Maybe your COG changed when you rebuilt it and the front to rear and side to side balance is a bit off.
Good luck.
'10 Ford F-450, 6.4, 4.30, 4x4, 14,500 GVWR, '06 Host Rainer 950 DS, Torklift Talon tiedowns, Glow Steps, and Fastguns. Bilstein 4600s, Firestone Bags, Toyo M655 Gs, Curt front hitch, Energy Suspension bump stops.
NRA Life Member, CCA Life Member