My items in my inventory and hotbar completely disappeared

When I was playing Minecraft on the Nintendo switch, I had left the game open for a few hours because I turned off my switch. Today when I got back on, the game was about to put me back where I was but it didn't. So what happen was that it sent me to my spawn point but took everything out of my inventory and in the hot bar. I don't know why this happened, but it did. So if you can fix this, please do. I had valuable items.