My wife’s friend of 30+ years cut off communications with her for no reason.
It really bothered her.
A few years later she called and asked outright why.
The explanation was essentially that she became frustrated that my wife’s life was going good and her own has become stagnant and she never really progressed in 30 years.

One the other hand, I have cut ties with a person because their life was a negative influence on mine.

Remember, don’t ask questions you aren’t ready to hear the answer.
You may find the issue is with your friend or you are the issue.

Is the answer really that important?
Either way the relationship is damaged.

I suggest focusing on closing this chapter and starting a new one.