To put it simply, the 87th TV series A Dream of Red Mansions was shot according to the annotated version of Zhi Yanzhai. When you say original, you should mean Cheng Jia Edition and Cheng Yi Edition. The difference lies in the treatment of the last forty chapters. In fact, Cheng Jiaben Cheng Yi Ben and the 87th edition of A Dream of Red Mansions are both sequels of Cao Xueqin's Dream of Red Mansions. Cheng Jiaben wrote a TV series "Dream of Red Mansions" earlier than 87 years ago. Because only the first 80 chapters of this book were Cao Xueqin's original works, and the last 40 chapters were lost, which was later continued by Gao E, the 87th TV series Dream of Red Mansions was not shot according to Cheng Jia's original works and Cheng Yi's original works, but was reinterpreted according to the first 80 chapters and more annotations of Zhi Yanzhai. I hope it helps you.
Actually, you don't have to worry. Just look at Cheng Jiaben and Cheng. For ordinary non-academic people, it is most important to have a complete work!