the dolphins die inside the water for not taking air

I think that is intended. Dolphins need air after around 4 minutes then they start suffocating. Did they have access to air above the water?

if they have access to air but almost do not leave the water

So they do they have air or not? Do you have a layer of clear space above where the dolphins are?

if they can go out but they do not come out very often and I see how they die in the water

in previous versions I noticed that they get out a little more but now they usually stay inside and almost do not get out

Confirmed !!! the dolphins do not leave the water often and sometimes they die because they do not reach to take air

they should do something so that the dolphins do not get fool and go out in time to take a breath

Cleaning up old tickets: This ticket has not been updated recently (~1 year+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.

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this keeps happening

Re-resolving as a duplicate of MCPE-37229, where this issue is tracked.