I've attached the .3mf file for the case where I get the random layer of infill floating in space. For my first example, the disc is the result of a 'revolve' operation in F360, so there should not really be a hole in it. This may be an F360 bug or even an error in the revolved profile in the sketch...
Yes, I'm seeing this too. I'm trying to set 60c bed temperature for layer 1, then bed heater off for all other layers. Even though I click 'update profile', this setting never gets saved. It's a real nuisance!