The path to fixing this requires first measuring and monitoring it, then establishing service level objectives that represent customer experience. Product and engineering teams have to agree on them. If the SLOs become violated, focus shifts towards system stability.
Getting everyone onboard is hard and that is why good leadership is needed. When customers start to churn because bugs pop up and new features are slow or non existent, then the case is very easy to make quality part of the process. Mature leaders get ahead of that as early as possible.