SUMMARY


STEPS TO REPRODUCE
1. Download this document: https://www.credit-suisse.com/media/assets/sub/docs/ch/privatkunden/konto-karten/mietkautionskonto/antrag-zur-eroffnung-de.pdf
2. Observe that the "Strasse" and "Nummer" fields show "undefined" in okular but  otherwise should be empty (ie in firefox/chrome pdf viewers).
3. Fill the fields with any value
4. Save the document
5. Exit Okular
6. Reopen document

OBSERVED RESULT

The field are filled with the value "undefined"

EXPECTED RESULT

The fields to be filled with whatever the user input was. 
N.B.: If the document is opened with some other pdf viewer then the correctly filled value appears (tested w/ firefox pdf viewer)

SOFTWARE/OS VERSIONS
Windows: 
MacOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION