Failed state registers as successful completion
Seems that in certain circumstances, when clicking on a number field to reveal its surrounding fields, you can get a win state even though you strike a mine. Possibly due to the order in which fields are uncovered?
In my screenshot below this occurred when clicking the field circled in yellow.
The issue was encountered on Ubuntu 18.04 running the snap packaged GNOME Mines application at version 3.36.0+git8.a3be8ab0