There is no definitive proof at all that this pipe is from the LM-5 last year. If you need that to believe, then you have given yourself an adequate excuse to not have to believe anything at all. The circumstantial evidence is what makes the piece convincing.

1) This piece is one of a few that appeared in the debris field of last year's LM-5 core stage descent that included the Ivory Coast along with the Atlantic Ocean.

2) The local Côte d'Ivoire villagers stated this stuff came out of nowhere. These pieces appeared at the same time that the LM-5 went down; May 11 2020 was the reentry, May 12 was when these objects were starting to be reported by the locals.

3) Also, a local infrasound Côte d'Ivoire station recorded rocket debris coming down at supersonic speeds not far from its location.

https://www.newsweek.com/chinese-rocket-rained-metal-ivory-coast-earth-orbit-1588865

4) Finally, China did not deny this claim at all. If it were so unreasonable/unlikely that those pieces came from the May 11 2020 de-orbiting of the LM-5 core module, why wouldn't China say so? It has made statements in response to this year's de-orbit but did not attempt to rebut last year's claim that those pieces landed on the Ivory Coast.

How do YOU explain the confluence of these bits of information if not that they collectively represent the falling of intact LM-5 debris onto the landmass of Ivory Coast???

The non-biased non-Chinese-ultranationalist average human being would find it reasonable to conclude that most or all of these pieces came from the de-orbited LM-5 module given the proximity in both time and space of the LM-5 debris field and of the objects in question.

BTW here is another article link that shows a photo of an object found on May 12 in the Ivory Coast which is also believed to have come from the May 11 deorbit of the LM-5 core stage: