The last 2 years our zucchini plants don’t get bushy at all. Right now we have blossoms on the plant and last year we got blossoms but the actual zucchini never got bigger than about 3-4 inches. Prior to this we never had any problem.
You may need to re-evaluate your current growing conditions of the plant does not seem to grow as it should. The small growth of the fruit, however, is likely due to poor pollination. Here is more information: https://www.gardeningknowhow.com/edible/vegetables/zucchini/growing-zucchini.htm