App frame rate drop when increasing devices refresh rate

Hello

So I'm noticing some frame and GPU utilisation increases when I change the refresh rate of the Quest 2

I'm using the latest OVRMetrics to view the numbers

App build with Unity 2019.4.34

Changing refresh rate using SideQuest

The app is a steady 72 when at 72hz GPU hovering around 85

If I change the refresh rate to 90hz the app hovers around 74-76fps but GPU goes up to 96

Going to 120hz pushes the GPU up to 99 and drops the app frame rate to 69-70fps

Is this to be expected? Or maybe its a bug with the OS (version 39.0.0.86.336)

I don't need the app running more than 72fps but even if I set the OVRManager.display.displayFrequency in Unity, the OS appears to override it when I change the refresh rate