Hello there, i recently wanted to try full body ik with procedural animations and when trying the full body ik solver i encountered an issue. I dont know where does it come from 
Hey there, I wrote that solver and would be happy to help you get to the bottom of this.
Can you try bumping up the Min Mass Multiplier and Mass Multiplier values? You can find them in the details panel when you selected the solver in the solver stack view.
Of course, thank you for your help. I let those values on default and moving them doesnt seem to affect the result
Okay, i tried differents settings on my blender export + bumping both values to a minimum of 5 and it fixed it ! Thank you a lot !
Glad to hear. The solver is somewhat dependent the size of the skeleton. So you probably had a very large mesh there.
Changing the ‘root behavior’ in the Full Body IK’ node to ‘Pin to input’ solved my problem.