Shudder

Car is shuddering / vibrating over 50kph, when coasting or lightly accelerating. Still happens when I’m in neutral rolling. It goes away if I accelerate hard.
the centre bearing rubber seems to have a fair bit of play, can move it with my hand.
Has only happen since adding a canopy and drawers + a fridge in the back which in total is 220kg.
I’m not to sure if the centre bearing is bad.
Thanks