You can always view the header information of a DICOM file with gdcmdump or dcmdump. For example, "dcmdump I0 > I0.txt" will generate a text file with the DICOM header from the problematic I0 image. This image was anonymized with the DicomCleaner while the other file was not:

(0008,0070) LO [PixelMed] # 8, 1 Manufacturer
(0008,1010) SH [EFILM_RAD1-PC_11] # 16, 1 StationName
(0008,1090) LO [DicomCleaner] # 12, 1 ManufacturerModelName

Specifically, the crucial private tags associated with the CSA header  https://nipy.org/nibabel/dicom/siemens_csa.html have been stripped. Without this, many of the sequence details are lost. I would suggest that when your colleagues run DicomCleaner http://www.dclunie.com/pixelmed/software/webstart/DicomCleanerUsage.html they should ensure to retain private attributes.