Why is my GRE score not improving despite studying? (plateau)

Maybe. First, check whether you're bouncing between the moderate and hard second sections. If you score lower when you reach the hard section and higher when you land in the moderate one, your totals can look flat even while you're making progress, just inconsistently. The first goal is to reliably reach the harder second section. A true plateau usually means you need to change your approach, not just study harder.