While on the minecade server, I was using the elytra crawl to make a level. i used snow layers to make the smallest possible crawlspace. when i stepped it up, however, while it worked in creative, when i tried in survival, i went through, then rubber banded completely out of the tunnel.

STEPS TO RECREATE

1.Enter a server and create steps using snow blocks, with each step 4 snow layers higher then the last. then, put a slab (In my case, quartz) one block above each step. (note: the bottom step should be level with the floor/leadup tunnel)

2.Obtain an elytra and attempt to elytra crawl through it in both creative and survival. it should rubber band you back to the start of the tunnel in survival, but work fine in creative.

The snapshot below is my setup built in a superflat singleplayer world for example.