This is a known issue — will update you when I have more info.
I’m excited to let everyone know that a new build that saves the theme setting is rolling out this week! I’ll mark completed once it’s fully rolled out.
Thanks for your patience!
An error occurred while saving the commentEd commented
I have never had a problem with losing this setting when using the 'Quit' option.
However if you click 'Sign Out' or 'Log Out' the theme preference is lost.