Created attachment 68557 [details]
If you edit the attached form in Poppler, the resulting file still shows the previous data when opened in acroread.
Steps to reproduce: Open file with poppler, change "12345" to "67890", save. Open resulting file in acroread, notice that it still shows "12345".
Some quick tests show that it's because acroread looks at the XFA dataset object (obj 66) instead of the /V property we set. Object 66 contains:
*** This bug has been marked as a duplicate of bug 18935 ***
on Mar 29, 2017 at 18:55:09.
(provided by the Example extension).