Basic loading of Cesium World Terrain- problem

I set up cesium+unreal OK on my laptop,
Now trying to setup on my PC and cannot load data from cesium, not even the Cesium World Terrain.
Produced a token, and allowed access in the cesium site… and don’t see any visible errors:
Any suggestions what is going on here?

It looks like you may have forgotten to enable “Extend Default Luminance Range In Auto Exposure settings”. See the Quick Start guide:

I’m following the instructions, and tried restarting the editor, and seem to be stuck in Step 3. section 9… (not getting a blue gradient:/)
What can I be missing?

What are you getting instead? Still white?