Work-life balance was affected when one of the tech representatives of our client did what we estimated was a 3 month work, in but a week. Since then, the weaknesses and lackings of the team became very evident.
I'd dare to say that the biggest problem was the agile methodology. One that didn't quite fit well in a team with a QA squad that reduced greatly our ability to adapt to change in the understanding of the domain. A lack of production environment also affected our need to iterate correctly over the product, making it impossible to discern the correct path ahead.
That, added to a team with little to no experience with highly resilient and scalable systems, ensured the termination of the partnership, regardless of the escape goats they desperately fired trying cling to this client.