What are some examples?
the 3 body problem would be a good place to start
There were similar claims by Google in 2019 regarding their breakthrough’s. It was met with a sizeable amount of skepticism. Here are some links from other articles.
https://www.science.org/content/article/ibm-casts-doubt-googles-claims-quantum-supremacy
https://www.techspot.com/news/105918-experts-cast-doubt-google-septillion-years-claim-new.html