A question about TrueAchievement

Hello there. This is my first topic created in the forum. I discovered this website after some time researching an incident I had with TrueAchievement.

To put in context. I have always considered myself a legal achievement hunter. I have endeavored to achieve all possible achievements in a legitimate and honest manner. Until the years passed and my time to play decreased as my responsibilities grew.

That is why I went to a friend of mine who assured me that I could get some expensive achievements quickly and legally. Silly of me, I believed him.

Some time later I decided to register on Trueachievement. At the end of 2020 they sent me an email telling me that they had identified achievements obtained illegally by outside programs and that they were going to remove my score from their website.

When reviewing the list I verified that they were the achievements that my friend had obtained me. So I could not defend myself because he was guilty. So I decided to unsubscribe from TrueAchievement.

I have been researching. My friend used the Velocity program to unlock the achievements. In theory, if done right, Microsoft can’t identify is cheated and ban you.

Going through the list of achievements that them identify I have seen that my friend did not act strange. He unlocked achievements in an orderly fashion and without doing everything at once. With different days and even months apart. He always unlocked the achievements online, if necessary, and without being games with a vigilance on top.

So my question is, how did TrueAchievements know? Is there a possibility to erase that trace of my achievements? Will they notify Microsoft?

I have been with my account for eleven years, I do not want to start from 0 or change it, or lose it. Any information you can give me I will appreciate