Happened to me again today on 1.16.221 on Windows 10. I lost my 3rd parrot to this bug in a few weeks + my brown panda as well 😞 - all these animals were underground, below many blocks so they were supposed to be safe from lightning.
This issue was resolved since then. I think it can be closed.
Resolved for me in beta 1.13.0.18
Resolved in beta 1.13.0.18
See MCPE-52435
Have you tried to change temporarily the difficulty to Peaceful?
Have you tried to destroy all beds (to make the raid successful) and then put them back?
Looks similar to this issue I reported about clocks: MCPE-52791
Root cause may be the same
See MCPE-52790
See MCPE-52790
I also experienced both issues multiple times (Windows 10).
I experienced the same issue
Were villagers confined in a single chunk?
In my experience, most mobs/villagers able to move across chunks will despawn eventually in Bedrock edition (unlike Java edition).
Probably a duplicate of MCPE-52435
Confirmed also with 1.13.0.16 Beta (Windows 10 - PC)
I experienced that issue multiple times as well, for all kinds of mobs that were not supposed to despawn.
The only solution I found is to keep mobs in a single chunk - as soon as they can move frome one chunk to another, they will eventually despawn.
Can confirm on beta 1.12.0.12: I have just experienced several llamas spawn on a platform with stone brick blocks (savanna biome).
Same issue on Windows 10, survival.
Same issue on Windows 10 as well
I had the same issue multiple times. The only workaround I found is to make sure the villagers/animals stay in one single chunk. If they can move from one chunk to another, they may despawn.
I still don't have the vanilla cape as of 14-Sep although I should be eligible (I own both games on the same account since long before June).