Minecraft Realms stops and then when you enter again, the world rewinds some minutes in time

When you are playing, i don't know why, sometimes the realms stops, you have to wait a few minutes and then, when you enter again, you realise that you have lost a lot of progress because the world had been rewinded. I play in my minecraft realms world with around 6 friends at the same time and this has happened 4 times.