The buses between Taichung and Lukang are small and often already full by the time they reach the first stop. As a result, they won’t stop unless there’s available space. I live in Taichung and had to take a bus to the Taichung Train Station because, by the time the Lukang bus reached my stop, it was already full and wouldn’t pick up any more passengers. It’s the same situation in Lukang-you need to walk to the first stop to catch the bus because they’re usually packed as well. This is likely why the buses didn’t show up at your stop. I don’t understand why the bus company doesn’t operate the route with larger buses.