Autocompletion after method call

I currently have some problems regarding autocompletion in PhpStorm. I added PhpDoc blocks to all my models which provide the return types of the methods. Furthmore, PhpStorm correctly recognizes the type the method returns as can be seen in the next figure.

But when we try autocompletion on that object it cannot give me any suggestions.

Though the class that is recognized by phpstorm contains plenty of things to autocomplete. Can anyone help me to locate the source of this problem? The problem occurs for multiple methods in different classes and also with different recognized classes.