Why doesn't the nested object get converted to XML when marshaled?

Question

Java

Can you please tell me why, when marshaling, one object stubbornly refuses to turn into XML and its package name, class and @ObjectId are simply indicated? In this case, the total mass of the remaining nested objects is normally transformed.
Annotations are placed - @XmlAccessorType(XmlAccessType.FIELD) @XmlType(...).
The result is:

<xmlRootObject>
  ...
  <innerObjectList>[email protected]</innerObjectList>
  ...
</xmlRootObject>

But it should be like this:

<xmlRootObject>
  ...
  <innerObjectList>
    <innerObject>
      <id>..</id>
      <field1>..</field1>
      ...
    </innerObject>
  </innerObjectList>
  ...
</xmlRootObject>

I see with the debugger that the object itself is correctly formed. Further, after the formation, it is sent for processing by WebLogic. (using javax.jws.WebMethod; javax.jws.WebService;)
I broke my whole head, I don’t know where to dig further, what are your thoughts / ideas?