Steps to reproduce (actual)

1. Walk and Sneak at the same time. (you can actually start walking a bit before sneaking and you won't get detected.)
2. Now wait a good 10 seconds or so. while not moving at all.
3. Unsneak.
4. Gets detected???
   Note: unsneaking by opening the inventory (with the Sneak set to "Hold") also gets detected.

Expected:

Step 1 would already get you detected unless you explicitly sneak before moving.

Step 4 would not get you detected.