Struggling to reproduce paper results before improving them — stuck below reported accuracy [R]

I’m a PhD student working in AI/computer vision, and I’ve hit a frustrating wall with a project. My supervisor asked me to improve the accuracy of a published paper. My first step has been to faithfully reproduce their results before trying any modifications. The issue is I can’t even match their reported baseline. The paper reports ~77% accuracy, but after multiple runs and careful tuning, I’m consistently getting around 73