Algodoo

This is because the white box is also glued to the other 2 boxes without the fixjoint!
Therefore, Algodoo sees the joint as connecting the two boxes with the white box. So this isn't actually a glitch, it's intended behavior!
(if im wrong please let me know!)

no the white box is only fixed to the box on the left, but for some reson the white box gets glued to the right box even if it wasn't glued in the first place.

i think algodoo thinks the gray boxes and the white box are all glued togther, and when the fixjoint gets removerd it doesnt know the other gray box (right) isn't glued to the white box so its glues it to the right one, but it thinks the white box is glued to the left gray box it thru (geometry actions) even tho its fixjointed the white box, so when it's fix joint is removed algodoo thinks the left gray box its being losened [if that the word] from only the white box thru (geometry actions) and not a fixjoint

Oh. You're right!