Is it obligatory for me to initiate phone contact with relatives unknown to me, given that I am unable to visit them due to my studies, the pandemic, and their non-compliance with precautionary measures?

Leaving the boycott with relatives, and communicating with them by phone or similar means, by offering greetings and asking about their well-being, takes one out of the state of estrangement, without being exposed to harm or distraction from studies or other interests.