Hi Mark,
To include a logo for the sticky header in the template, some customization is required. Here is possible approach:
1/ Add a new option in the template to upload a logo specifically for the sticky header.
2/ Customize the header block to load this new logo.
3/ Define the necessary CSS styles for the sticky header logo.
If you’re not familiar with coding, our developers can assist you in implementing this quickly and professionally: https://www.joomlart.com/service/joomla-website-development-service
Best regards