Rejoining my world keeps resetting my character?

[Lady_]

I play on Switch

I host a public server to play on. I turn off my console after nighttime and the save completes. When I come back to play, I am prompted to choose my character and spawn at the portal with zero inventory and lost map progress, but the world itself is untouched? 

My character also periodically spazzes, meaning it walks back and forth quickly and I can't do anything unless another player comes and touches me (for some reason that 'frees' me). 

I've had the game for 2 days and already these two bugs. How do I fix them?