In a recent lengthy and in-depth investigation, AnandTech found a very interesting "optimization" on the OnePlus 9 and 9 Pro when it comes to various apps. In essence, the OxygenOS analyzes the apps it will more often than not limit the performance in what we assume is a bid to extend battery life. However OxygenOS would not offer the limited performance to benchmarking apps, which Geekbench sees as cheating. That's why Geekbench took the action of removing the OnePlus 9 and 9 Pro from its database. Geekbench says that the system makes performance decisions based on the applications'...
Source: https://www.gsmarena.com/geekbench_delists_oneplus_9_and_9_pro_over_benchmark_manipulation_allegations-news-49931.php