CorelDraw 2020 Desktop theme changes are not holding

I have had CorelDraw 2020 installed for a week now and I can't get changes made to the desktop theme to hold from one session to the next. I use the dark mode with custom colors for the desktop and border. When I close one session and reopen CorelDraw 2020 for a new session, the desktop theme has reverted back to the original default settings. How do I get my changes to hold as the new custom default? I didn't have this problem with CorelDraw 2019.