Is boycotting irreligious relatives and refraining from visiting them because of the niqab considered a severance of kinship ties, and is a phone call sufficient to maintain kinship ties in this case?

Maintaining kinship ties is obligatory and is achieved through communication, correspondence, greetings, and anything that is customarily considered a connection, and it is not limited to visits. If one maintains some ties but does not achieve their ultimate extent, they are not considered a severer of ties. However, if one falls short of what they are capable of, they are not considered a maintainer of ties. If custom dictates that kinship ties are maintained without visits, then you are not obliged to visit, especially if you fear the gazes of non-mahram men. However, you must maintain ties with them through communication and other means that do not cause harm to your religion or your worldly life.