My Workmaster 37 does the same thing. I think it’s caused by the higher viscosity of the ambient temperature hydraulic fluid on startup causing the systems pressure relief valve to chatter. This would cause pressure fluctuations in the system which shows up with the bucket doing the dance when you first lift off the ground. It disappears pretty quickly as the fluid warms up ( and thins out). It’s seems to be a LS thing as my Shibaura built New Holland’s have never exhibited these symptoms.