bookmarks from docx titles fails: first few correct, de rest is just repeating de last correct one

Hello there

Just a couple of days ago, I noticed that the headers of  DOCX files that we have used for ages, suddenly do not get their headers (titles) properly converted into bookmarks in PDF. The number of bookmarks seems correct. But only the first couple are labeled and linked corretly, then the last correct one just gets repeated (label and link incorrect). This is even the case with the DOCX'es we justed some years ago. And the problem is consistent for all DOCx'es.  So far only on my machine. (I did an 'repair installation' already)

thx for any info

Herwin