What is the ruling on a paternal uncle's act of secretly abandoning the duty of guarding villages entrusted to him? Is it permissible to accept his invitation to a feast, sometimes knowing of his betrayal?

The uncle is not permitted to violate the terms of the contract, based on the words of Allah Almighty: "O you who have believed, fulfill [all] contracts," and the words of the Prophet, peace and blessings be upon him: "Muslims are bound by their conditions." The uncle is not entitled to any part of his salary except that which corresponds to his work. If he has other lawful wealth, then it is permissible to deal with him and eat at his place. He must be advised that his action is forbidden. If refusing his invitation would deter him, then decline; otherwise, accept his invitation and continue to advise him.