I've been having similar issues, but the marketplace has been working for me. The issues only arise when I am trying to connect to a server. When I get to the loading screen, the game freezes, at which point I can go to the Nintendo Switch home menu just fine. But when I try doing anything, it won't load and I can only access the quick menu, where the option to go into sleep mode doesn't work. If I try to close Minecraft before doing something else, the Switch freezes entirely, at which point I can't even access the quick menu. I have to hold the power button and perform a hard power down.
Michael H
I've been having similar issues, but the marketplace has been working for me. The issues only arise when I am trying to connect to a server. When I get to the loading screen, the game freezes, at which point I can go to the Nintendo Switch home menu just fine. But when I try doing anything, it won't load and I can only access the quick menu, where the option to go into sleep mode doesn't work. If I try to close Minecraft before doing something else, the Switch freezes entirely, at which point I can't even access the quick menu. I have to hold the power button and perform a hard power down.