I remember learning in halacha that a Ger disowns his pre-conversion family. That he may no longer maintain contact with them and they are no longer considered his parents/family.
That’s probably something you read, but it’s not what a rabbi will probably say.
I’m not a rabbi, so I’m not going to paskun, but I’ve been told by my rabbi & shown the source(which I forgot now), that while a ger isn’t considered a part of his old family, he still doesn’t have to mention that or break contact with them. This was a decision made with something to do with inheritance issues. Just ask a rabbi to explain it.