When the player is 0.30001m to 0.31m from a block, ceiling collision related to shifting and crawling stops, but other collision works.

How to Reproduce

1. Download and open attached world
2. Use the lever on the command blocks

This can also be done without command blocks

1. Shift under the upside down stairs or crawl under the hopper
2. Hold shift and move to the edge of the block
3. While holding shift and moving towards the edge, jump
4. Stop moving, then release shift.
5. Repeat steps 3 and 4 until you stand up

Observed Result

The player stands up, but stays on the block, clipping into the stairs/hopper above.

Expected Result

Either the player falls off the block or stays crouching/crawling.