FWIW, I've had good luck handling schedule changes by reaching out to the social media team via FB messenger. For whatever reason, they seem to be more empowered or willing to help than phone agents and even phone supervisors. A 5 hour change is pretty significant. If you reach out, you could explain, "there was a significant schedule change to my award ticket and I was hoping someone could take a look to see if anyone there or in the Star Alliance liaison team may have any solution that could get me a departure and layover time closer to what I had previously scheduled". Even if they can't come up with an alternative, at least you will have saved yourself hours of frustration on the phone.

good luck!