Steps to reproduce:
Crouch next to water
Jump in water
You'll no longer be crouching
You can reproduce it this way too:
Enter fly mode
Crouch (fly down)
You'll stop at the water surface because you'll no longer be cflying down
Linked issues
is duplicated by 5
MCPE-111050
going into water makes player exit sneaking
Resolved
MCPE-144621
Shifting resets when passing through water.
Resolved
MCPE-176205
Stepping into a body of water/flowing water deactivates your sneaking/shield
Resolved
MCPE-176740
Entering water/touching flowing water while sneaking causes the player to unsneak
Resolved
MCPE-179272
Sneaking into a body of water deactivates sneaking
Resolved
Comments 3
Thank you for your report!
However, this issue has been closed as Working as Intended.
This has been added to prevent players from accidentally drowning (pressing sneak again allows the player to descend if need be). If you need help or have a suggestion you might like to follow a link below.
Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki
Confirmed. Probably caused by the fix of MCPE-38212.