Why is خَاسِئِينَ mansub in مَا انْفَكَّ الْمُسْلِمُونَ خَاسِئِينَ?

The Khabar of Defective Verbs

• It is the ism of مَا انْفَكَّ.
• It is the mansub khabar and a sound masculine plural.
• It is a majrur adjective.
• It is a direct object.