The bug
Baby turtles take (suffocation?) damage when pushed or moving against the ceiling. This is similar to MC-50367, but apparently not exactly the same problem since it looks like their eye level ends below their hitbox.
How to reproduce
Build an upwards bubble column (soulsand) with a solid block above (e.g. stone)
Spawn a baby turtle inside the bubble column
→ ❌ The turtle takes damage below the ceiling
Related issues
is duplicated by
relates to
Attachments
Comments


I rewrote your report to describe the problem a little bit clearer. I hope you are fine with this.
Confirmed for 19w13b

Confirmed for 20w11a

In 20w12a

In 1.16 Pre 3
Can confirm in 20w51a. I'd just like to add on that there must be a solid block above them in order to reproduce this issue. I tested this with slabs and was unsuccessful.