I don't doubt that a model rocket of the full sized crickett flew poorly.

The real cricket was tube launched. As it was an impulse launch rocket it attained maximum speed after traveling only 2 body lengths. Thus, the tiny fins were more than enough to make it fly straight as an arrow. Model rockets are not very fleet of foot off the pad and have a protracted burn time for the most part, thus the terrible flight characteristics of an exact, full sized replica of the crickett.

Not enough air over the tiny, true-to-scale, fins early in the flight.