Eclipse中的Content Assist在某些文件中没有显示变量的提议

I have a problem with Eclipse (Neon.3 v4.6.3 in CentOS 7) Content Assist for PHP. There are cases in certain files where Content Assist returns 0 proposal even though there are a lot of options. This happens in one file (at least). For most of files it works great.

In the file that I am mentioning I have three cases where it works only for one and fails in the other two. It does not work when I write $this-> or when I set the type of a variable within the method with // @var MyClass. It works though when the variable comes from the method's parameters (type defined in function comments). See example:

/**
 *
 * @param MyClass $myObject
 */
public function myMethod($myObject) {
    // CASE 1
    $myObject->something; // here I can see Content Assist options and select when writing $myObject->

    // CASE 2
    $this->something; // here I cannot see Content Assist options when writing $this-> (I see a window saying 'No Default Proposals')

    // CASE 3
    // @var MyClass $myObject2
    $myObject2= getMyObject2();
    $myObject->something; // here I cannot see Content Assist options when writing  $myObject2-> (I see a window saying 'No Default Proposals')
}

It feels as if this file is stuck and does not recalculate for the Content Assist. Can I somehow force it to recalculate or is it something else that is wrong?