What is the ruling on deeds performed by a Muslim during a period of dispute or estrangement, and are they accepted or rejected? What if he dies in that state?

It is not permissible for a Muslim to abandon his brother for more than three (days), especially parents. The Messenger of Allah, peace and blessings be upon him, said: "The gates of Paradise are opened on Mondays and Thursdays, and every servant who associates nothing with Allah is forgiven, except for a man between whom and his brother there is animosity. It is said: 'Wait for these two until they reconcile.'" It is apparent that they are deprived of forgiveness until they reconcile. The act of the disobedient servant in abandoning is valid, and its acceptance is up to Allah. It is hoped that Allah will accept it if it was for His pleasure. Whoever dies while abandoning is disobedient, and his matter is with Allah. The one who is abandoned should not stop performing supererogatory acts and good deeds, for "indeed, good deeds do away with evil deeds."