I personally feel that now that his father has passed away, I'm sure there are many things at home, and he faces many challenges and pressures.
Is it possible to get to know him better and get through the difficulties with him? This will give you a basis to meet a friend in need.
Personally, don't ask him why he doesn't reply to the message, which will increase his pressure and make him feel that you don't understand him.
I wish you an early resumption of contact and hope to help you.