I was hoping the latest release would fix this but I'm pleased that a workaround is possible by changing the view and staging files.
When using the No staging view it should be possible to select and deselect the Push changes immediately to [branch] checkbox so that I can decide if my commit should be immediately pushed to the origin branch.
Currently, if a file is staged in split view, when you change back to No staging then the file is ticked and the Push changes immediately to [branch] checkbox is enabled and remains enabled even if you untick all staged files. The Commit button reacts as expected - it's only possible to commit if at least one file has been committed.
It looks like the Push changes immediately to [branch] checkbox is only enabled when a file is staged in split view.
It should also be enabled if a file is ticked in No staging too. Optionally, it could also be disabled if no files are ticked.
This issue is fixed in the Release '3.4.20'