hit a plateau
To reach a certain level of achievement or success but then stop progressing beyond it. Ugh, I'm not losing any more weight—I must have hit a plateau. We've hit a plateau and have stopped attracting new customers.
hit a plateau
Fig. to reach a higher level of activity, sales, production, output, etc., and then stop and remain unchanged for a time. When my sales hit a plateau, my boss gave me a pep talk. When production hit a plateau, the company built a new factory.