Why are my minecarts with chests not automatically bouncing between two powered rails?

I watched a tutorial and all they had was a lever and a powered rail and it would bounce between the two. When I try this, the chest won't get moving until I bump my body against it. From some Googling, I've found that powered rails are speed multipliers, hence why speed = 0 x 2 = 0. Is the block supposed to 'bounce' the cart back thus giving it speed in the opposite direction?

I created a more elaborate version (see second image) but still having the same issue. Any clues?

Bedrock 1.21.51 (21st of December 2024) by the way.

https://preview.redd.it/vlaq1nz2278e1.png?width=2561&format=png&auto=webp&s=20766737fda00054ee799151f720b324979c0188

https://preview.redd.it/ic2ojsr3278e1.png?width=2557&format=png&auto=webp&s=9568d7080a207cf421d60f4c116ee560c42e1ab5