I have created an update to the version 3.3.0. since the update I get only 503 error messages in the app.js. In addition, the application is extremely slow. The iis reports constantly that the application was shut down.
I think the reason could be that the migration fails and therefore IIS restarts the app all the time and is obviously slow. If you send me a backup of your DB I can have a look. Which was the version you have used before 3.3.0?