Changing the Y velocity of a Humanoid?

I have the following code:

script.Parent.Touched:Connect(function(hit) local humanoid = hit.Parent: FindFirstChild("Humanoid")

if humanoid ~= nil then for name, child in pairs(hit.Parent:GetChilderen()) do child.Velocity = child.Velocity + Vector3.new(0,200,0) end end end)

With this code, when the humanoid jumps into the part (cancollide off) the humanoid has a boost mid jump. However, the humanoid glitches a bit in the air and sometimes freezes for a milisecond, and proceeds to continue on his decent to the ground without any benefit from the part and the code.

I have edited the velocity values manually when testing the game, and the humanoid does not move in the Y direction at all, but does move along the X and Z a bit.

Any help would be beneficial, I just need a way to move the humanoid mid jump and flight.

Many thanks in advance, P3tray.