SUMMARY
When exporting a contact with a phone number marked as cell phone to vCard (I tested vCard 3.0 and 4.0), this phone number is not being exported, if "Other fields" is deselected during export.

It is very puzzling that cell phone numbers are categorized as "other".

STEPS TO REPRODUCE
1. Create a contact with a cell phone number.
2. Right click "Export".
3. Choose vCard 3.0 or 4.0
4. Deselect "Other fields" (in fields to export)
4. Save to file.
5. Open exported file and find the cell phone number missing.

OBSERVED RESULT
Of the four phone numbers saved in the contact, only three were exported to file.

EXPECTED RESULT
Cell phone number should be exported.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Debian Bookworm
KDE Plasma Version: 5.27.2 
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
None.