Xbox Splitscreen Inventories and XP Lost

When we recently signed into our family Minecraft world, we were surprised to find that our inventories had been erased. The host had all of their armor and gear, but our other three accounts were placed in spawn without any of their previous gear, tools, or XP. All of the builds we have made are still in the world, but our inventories (except for the host) have been wiped. We all use individual Xbox accounts (not guest accounts), but this still happened anyway. Please help us fix this.