We had an issue on a Drupal 8.8.2 site, had to restore DB, Core and Vendor, now anyone visiting the site gets the site as normal, but if admin logs in I receive:
Drupal 8.8.2 Drupal already installed - To start over, you must empty your existing database and copy default.settings.php over settings.php. - To upgrade an existing installation, proceed to the update script. - View your existing site.
Of note: Rather then restore over existing db I created a db2, restored the DB to it and pointed the settings to it (not sure if that is the issue)
I can't figure out how to stop that page from loading. I don't want to start over, running the update script does nothing but bring me back to the same page. View your existing site does take me to site but can't edit anything (looks like it just logs me out).