This means the Apache version on the web server is outdated. CGIPassAuth requires at least Apache version 2.4.13
It sounds like MySQL is not deleting all the relevant files when you drop the database. This post might help: https://stackoverflow.com/a/24107982
If all else fails, you should be able to create a new database with a different name and use that instead.
I see the Solved label has been applied - if anyone has this issue in the future, it means the Cobalt template is not up to date, so updating to the latest version of that template should solve the problem.
The .htaccess file is included within each Nameless release. You can find the version 2.1.2 file here: https://github.com/NamelessMC/Nameless/blob/v2.1.2/.htaccess
Note most web hosts hide these files in their file managers - there should be a setting to stop hiding them (if you cannot find the setting, please contact your web host for assistance), or if you use an FTP client like FileZilla or WinSCP then the files will not be hidden.
Typically this means that your domain is not pointing to the web host correctly.
Or, if you have an A record for your domain that points to your web host, and one with the same name which points to your Minecraft server, this will not work either. Instead, you must use an SRV record to point to your Minecraft server: https://www.namecheap.com/support/knowledgebase/article.aspx/9765/2208/how-can-i-link-my-domain-name-to-a-minecraft-server/