How can our team influence changing to a more long - term view focused on improvement and root cause guided action?
In my personal experience, audit goals have nothing to do with root causes.
They just look for violations of policy and standards, then report to management. "Passing the audit" any way possible is the sole goal of the teams being audited.
This isn't a surprise. If you put a lot of emphasis on "adhering to standards" then the teams that want to get real work done often find it more efficient to put minimal effort into adherence, due to pressures to get things into production more quickly. The standards are considered a burden, overhead to be avoided as much as possible. And to some extent Agile is encouraging teams to move away from such strict SDLCs and more toward lighter, more streamlined methodological processes that meet the more immediate needs.
Consider that you may be in the wrong department if you want to make real change happen. For change to happen it must be a commitment from the top. And most likely that commitment won't target the Audit team as the change agent.