I could see AI scoring artificially high on IQ tests in a similar way to how it performs artifically well in chess.

As I understand it, chess AI isn't actually particularly good at playing chess intelligently, it's just that high level chess devolves into memorization and computers have an infinite ability to memorize scenarios.

In a similar way, from what I remember from taking an IQ test as a child, the tests are built on the assumption that the test taker has a finite memory and a finite amount of time to learn. In that case, having learned and remembered an unusually large amount for one's age could reasonably correlate with intelligence. However, without that limitation, the ability to answer the questions may not actually correlate with intelligence.