What is Islam's ruling on dealing with a maternal uncle who suffers from an obsession with suspicion and espionage, and a grandmother who believes him, which has led the mother to prevent her daughter from visiting the grandmother for fear of harm and monitoring by state security?

Allah the Almighty has forbidden spying and enjoined the avoidance of much suspicion. Your uncle's accusation against you of a sinful, reprehensible act is impermissible unless proof is established. The matter worsens if he adds insults, beatings, and humiliation to the accusation. Try to clear yourselves to the best of your ability to preserve affection and kinship ties. If that does not work, then avoid visiting him without severing ties completely. Content yourselves with the minimum level of connection, such as greetings, phone conversations, and asking about him. Forbidding the oppressor is permissible if he persists in his injustice after being advised and warned. It is commendable for you to maintain ties with those who cut you off and to be kind to them even if they treat you badly. Whoever does so is as if he is feeding them hot ashes, and he will always have a supporter from Allah.