Anytime travelling from the Overworld to the Nether, all tamed and persistent animals in the Overworld disappear. this is true even when playing LAN games. This makes catching, taming, and breeding animals completely pointless as they all disappear,
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duplicates
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Dr.Awesome4333
Thanks for the report, however this has been reported before as MCPE-8002, please search before creating a ticket as it is likely that someone else has reported already.
Side note: This has been fixed in an upcoming update.
Please address this issue as it is quite frustrating. Thank you