Cannot adjust tileset location


I have converted an IFC file to 3D Tiles in FME with the Cesium 3D Tiles writer.
This results in one JSON file and B3DM files.
When I try to add the data to Cesium ION, the tileset does load but I cannot adjust the tileset location.
When I hover over the ‘Adjust Tileset Location’ button, the mouse cursor changes into a forbidden / prohibition sign.
Only the bounding box of the tileset is shown, but nothing is in it.
I use the correct coordinate systems for reading and writing of the file, so I do not think that’s the problem.

Below is a screenshot of the My Assets page of Cesium ion with the bounding box of the tileset shown.

Does any of you know how to fix this issue?

Thanks in advance,