The Wanium theme comes with 2 theme options (“Appearances > Customize” & “Page options at bottom of the page/post”)
So in case you see the customize option doesn’t change as in “Appearances > Customize”, please just have a look at the “Page options at bottom of the page/post”.
It’s very simple indeed, just 2 points that you need to know to use our Theme Options.
1. There are global options that affect you entire site in “Appearances > Customize”.
2. There are individual options that affect only that page or post in “Page options at bottom of the page/post” (Screenshot: https://i.ibb.co/zS2J3j4/po.png)
If you want to use global options (1), please set those options as “default” in individual options (2).
So in this case, please go to your page editor, scroll to bottom, and remove the custom logo in order to use the default logo in “Appearances > Customize” as in the screenshot here: https://ibb.co/1vVn3dz
If the problem persists, please share us the admin account of your site so we can investigate your case and help you out. Also, please point to specific page where we can see the problem.