When sneak is toggled on and you open your inventory you stand up when you close your inventory you sneak again. I have my sneak key bound to “C”. Sneak: Toggle
Linked issues
duplicates 1
Comments 2
Duplicate of MC-301806 which is working as intended.
This is not a bug. Until a few snapshots ago that was an unintended feature, so they removed it.
However, you could try to join to the petition made on the Minecraft feedback website
(MC-163218 )