Note: i'm not sure what version of bedrock it is

After pushing a tamed cat into the nether while following you the realm seems to break and reload from the most recent back up , this then acts like a time travel that lets you reset anything that happened from last save to you putting cat in nether and entering.

simple instructions :
get a pet cat and a nether portal

make the cat stand

then push into the nether and enter with it

everyone on realm will be disconnected

and join back to an older version of world