ASP.NET Razor C# appearing as text when publishing via file system with custom domain

I have a CSHTML web page in which a user completes a survey in a form (with method post) block and there's c# razor code that is adding the answers to the survey into an SQL server database. Via file system, I have published the website with a custom domain, but for some reason, when I browse to the link with the survey, all the c# razor code is visible at the bottom of the page. I'm not sure how to hide that code.

Here is an image of what the webpage looks like

I tried submitting the survey regardless of what was visible at the bottom, and got the following error.

HTTP Error 405.0 - Method Not Allowed The page you are looking for cannot be displayed because an invalid method (HTTP verb) is being used.

Detailed Error Information: Module StaticFileModule Notification ExecuteRequestHandler Handler StaticFile Error Code 0x80070001 Logon Method Anonymous Logon User Anonymous