This is because your pano does not contains XMP data that facebook needs. I tried to paste your pano into image that works and resave it with photoshop, but it looks like PS just overrides XMP with hes own data. What works for me, is to add needed XMP data with small android app called photosphere XMP tagger (one click solution), or to use exifTool with exifToolGUI and copy paste XMP from donor photo (unintuitive and cumbersome to use, but very powerfull).
p.s. your pano should be 2:1 aspect ratio, i.e. 4000x2000 px