Steps to reproduce the issue

Create some frontend links in the administrator, for example in an HtmlView::display and visit the view

        $link = \Joomla\CMS\Router\Route::link('site', 'index.php', absolute: true);
        echo "$link<br>";
        \Joomla\CMS\Uri\Uri::reset();
        //correct cached
        $link = \Joomla\CMS\Router\Route::link('site', 'index.php', absolute: true);
        echo "$link<br>";
        //administrator
        $link = \Joomla\CMS\Router\Route::link('site', 'index.php?b', absolute: true);
        echo "$link<br>";

Expected result

https://example.com/
https://example.com/
https://example.com/?b=

Actual result

https://example.com/
https://example.com/
https://example.com//administrator/?b=

Additional comments

The second link is returned from cache.