From BIV on 25 August 2023:

Amid rising demand, thousands of customers lost bookings in recent weeks when first Coastal Celebration and now Coastal Renaissance went out of service with mechanical problems.

Engine problems sidelined Coastal Renaissance, which is likely out of service until at least mid-October.

On Wednesday, the third of the three Coastal-class vessels, Coastal Inspiration, was delayed because of what the company called a minor issue. Service was normal on Thursday.

The German-built Coastal-class vessels are critical to the system, especially during the summer. They run between Vancouver Island and the Lower Mainland

https://biv.com/article/2023/08/resilience-put-test-bc-ferries-tries-cope-high-traffic-staff-shortages-vessel

The three Coastal-class ferries, only 16 years old, were built in Germany to reduce costs. Canadian shipbuilders protested the decision but the Conservative Government in 2007 went for the lower German price.

That these ferries should all break down in the same period casts doubt on that decision.