1 Copper

Dell XPS 13 7390 (210-ASUT) Ubuntu will not boot to desktop

Dell XPS 13 7390 with Ubuntu, purchased from Dell in December 2019.

It was working great until today when Firefox disappeared.  After I closed Firefox I couldn't start it again, it just wasn't there (at least search in GUI and terminal couldn't find it). So I went for lunch and when I got back it wouldn't let me sign in (password wasn't accepting any characters), so I pushed power button to turn it off. 

Turned it on and it boots to command prompt instead of GUI.

 I run 

sudo systemcd set-default 

It loads desktop background and that is all.

Any suggestions how to resolve this?