ReLive driver locks my monitor to 60hz and does not allow it to run at other refresh rates. Rolling back to 16.11.5 and earlier fixes it.
See here: https://streamable.com/1hvq
This issue persists after reboot and some intensive troubleshooting. Conclusion: driver bug. Please put this into known issues.
My GPU is a R9 Fury X and my monitor is a BenQ xl2735