Hi @JBlak ,
You can enable the "Show header and navigation" feature in a SharePoint site using SharePoint Online Management Shell (Replace "https://yourtenant-admin.sharepoint.com" with the URL of your SharePoint admin site, and replace "https://yourtenant.sharepoint.com/sites/yoursite" with the URL of the site where you want to enable the feature.):
Connect-SPOService -Url https:/yourtenant-admin.sharepoint.com
Set-SPOSite -Identity https://yourtenant.sharepoint.com/sites/yoursite -ListsShowHeaderAndNavigation $true
Result:
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