I've got a problem with my .NET Core 5 Razor Pages application. I am developing an application on Windows 10. This is a Razor Pages app where I have a form with validation. The data from the submitted form is put into the LiteDB database, and the EmailSender service cyclically downloads the latest 5 messages from the database every minute and sends them to me by e-mail using MimeKit.
Everything works fine until I deploy the application on Ubuntu where I have nginx as reverse proxy. Validation error messages and message content do not contain Polish characters. I also have Polish characters in the content of the page and they are displayed correctly. When I run the application from Visual Studio in Windows 10, everything is fine and Polish characters are supported both in the email and in the form validation error messages.
In Ubuntu I have the locale set to en_US.UTF-8 and in the _Layout.cshtml file I have the charset set to utf-8. I have no idea what could be wrong, please give me some suggestions.