I am having similar issues plus more.
I had to re login to Microsoft and my created characters were gone. I had to start over.
I'm logged in and connected to the internet and have multiplayer ready. When I go into my sons and mines world, it says: "Oops! Your Microsoft Account was disconnected. To invite more players, sign in on the Main Menu and restart your world." But according to the Main Menu I am logged in to Microsoft.
When I quit the game and closed the software my Switch froze for about a minute before closing the software.
It's still happening to me. It seemed to have been fixed with the update (though I was on a new Realm) and now I've been sitting here for 2 minutes trying to open a barrel.