Not saving my realms and disappearing shulker boxes.

First problem huge lagging and not saving the worlds properly. Always when i quit the realm and when i am back all of my shulker boxes disapear and i struggle a lot to get them back from quiting and going back to the realm. When i save the realm and get back from a break my realm is not saved anything and i have to work hours to get the diamonds or redstone projects back. My realm members are suffering from these bugs too. It will help a lot to fix these bugs and me and my realm members will appreciate it a lot!