When using an elytra, periodically my player will render as only being one block tall, this causing me to walk around, accidentally fall into a one block space, and start suffocating.  It is as if my player is two blocks tall, but my top half is transparent and will let me walk through blocks, while still suffocating and not being able to see anything.  This is not me flying into a one block space, this can happen every once in while, is random, and happens after landing from flight.  I don't see any pattern or cause on how or when it happens.  The only way I found how to fix it is to constantly jump and use my elytra until it sees me as two blocks tall and I can't walk into one block spaces.  This does not fix it permanently, and after a while the glitch will come back.