Camera east north up reference frame navigation quirks

Hello Cesium community! This is my first post on this group so please be kind.

I am working on a mockup involving Cesium. Our use case requires the camera to be rotated as if you were standing on Earth like in a first person shooter.

After finding the Cesium.Transforms.eastNorthUpToFixedFrame method and figuring out how to use a transform matrix, I managed to rotate the camera to this orientation.

Then I created a ScreenSpaceEventHandler to make the camera react to mouse input. Now when the camera gets close to 0 tilt, it snaps to tilt 0 and starts animating the SkyAtmosphere (I think). I have searched high and low to find what causes this but as of yet to no avail.

You can find the mockup at

How can I disable this snapping and atmosphere animating behaviour?

Any suggestions are welcome!

Well I have found the answer. I was only setting camera direction and camera up values, thinking that the setters would handle updating the other values. This is not the case.

Setting the direction, up and right camera values solves the issue.