I hope you are well today and thank you for your question.
Please make sure that you have selected the appropriate header template in the theme header settings as shown in the attached screenshot.
If the issue still persists then would you mind if I log in to your site and do some troubleshooting? If this is ok then could you please temporarily share me your site admin login details privately by adding them in the box having text “Enter your private content here (only you and forum moderators will be able to see it)”?