Only returns proper ctx.body if on a route other than home
I have a piece of middleware like this: 

```
    app.use(async (ctx, next) => {
      await next();
      console.log('DUUUUUUUUUUUUUUDDDDDDDDDDDDDDDDDDEEEEEEEEEEEee');

      const memoryIndex = await middleware.devMiddleware.fileSystem.readFileSync(memoryIndexPath, 'utf8');
      const blah = await memoryIndex.replace('[replaceme]','[hey]');

      ctx.body = blah;

      // ctx.body = 'yaaaaaaaaaaaay';
    });
```

It only returns the correct ctx.body on page OTHER than the home page, although I can see through the console.log that it gets called. Any ideas why that would be ? 


