Destruction of death in family

When i was 17, my grandma died. She was the one who keep us together all the time. Thanksgiving, new year, etc. Everything was happened in her home, with her foods that she prepared for us. And after she died, everything changed. Since 2020, no one in family cares each other. No one talks with others. Maybe 1-2 in a year. It was so normal for a like 5 years but on last months, it become weird for me. I was just accepted that. Now i want to know why it happened. Any suggestions?