UNC path(\\path...) help documents within User-defined features (UDF) are not working in managed mode.
Solution
Work-around is for the user to add an extra backslash, i.e. \\\folder\some.file.ext, instead of \\folder\some.file.ext.
Note: Native NX does not have this issue.
Notes and References
Hardware/Software Configuration
Platform: INTEL
OS: windows
OS Version: 10_1909
Product: NX
Application: DESIGN
Version: V11.0.2
Function: FEATURE_MODEL
Ref: 001-10037045