I was looking through the newest release "monsters of the multiverse" and it shows that alotof the races I have purchased from previous books are that I don't own them minus a couple and I am still able to access them in my character creator. Just wondering if this is a bug or if it is a something new like updates to races have to be repurchased.

Most of the MotM content is considered new and separate from old content. Content you already own that was not changed, it will still say is owned, but if it was changed you would need to buy the new version yo use it (not really needed to be honest, mostly minor changes).

Tldr Not a bug.