counterintuitive
adj.adj. describing something that is hard to understand because it goes against what you expect. It feels like the opposite of what common sense would tell you.
adj. contrary to what one would intuitively expect; difficult to understand because it goes against common sense or instinct. Often used to describe complex systems, data, or logical conclusions.
The solution to the puzzle is actually counterintuitive.
Many people find it counterintuitive that adding more lanes to a highway can actually make traffic worse.
The software's interface is intentionally counterintuitive, designed to prevent users from performing high-risk operations without a thorough understanding of the underlying data structures.
From counter- + intuitive. Coined by Noam Chomsky in 1955 as “counter-intuitive”.