This is one of those not-sure-if-bug-or-feature issues..   On my dual-boot Fedora/Win7 system, I needed to access a ‘shared’ NTFS (ntfs-3g) partition.   When I came to add a softlink to the NTFS partition on the Plasma Desktop, the link existed, but nothing showed on the Desktop.    Other softlinks – to EXT4 partitions – displayed OK.   I tested with an NTFS softlink in a directory (using Dolphin) but this did not show up either..

The fix (workaround?) is to use ‘Create New / Link to Location (URL)‘ instead, and this displays and works OK.

The link file contains:
[Desktop Entry]
Icon=folder
Type=Link
URL[$e]=file:///win7ssd01/

Robert Gadsdon.  March 26, 2019.