I am not really sure how to help you. I simply have never seen dark mode. My theme in Add-ons and Themes is default, although the light theme gives me the same result. However I have customized windows to not force dark themes onto applications. Perhaps that is what you need to do.

Matt,

Thanks very much for your help it simply hadn't dawned on me that it might be the theme. I changed it yesterday coincidentally at the same time as a version upgrade. Thank you for putting the theme thing in my mind.