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It could be stress, adjusting to a new home or it could be a neurological problem that occurs sometimes, if it is that then there isn't a cure but you can help by adjusting your set up.
Your ham might do better in a cage on one level, plenty of small hideouts, just things like cardboard boxes, egg boxes or toilet roll tubes might help, with a layout that isn't set up with a large space in the centre or too much space around the edges of the cage, that might help your ham engage in more natural behaviour.
If it continues like this it would be a good idea to get a vet to give your ham a check over too, sometimes even things like ear infections can interfere with balance & cause strange behaviour.
If you do go to the vet I would show them the video so they can see how he behaves in his own environment as he may behave differently at the vet.