Line Between Arrows disappears, when Tolerance Type is Equal Bilateral Tolerance.
Same issue is also appeared if the dimension has no tolerance but has 'after' appended text.
This behavior has been there for long time.
Solution
Workaround for this issue:
1. If all the text is outside of the extension line, then the display is correct.
2. Change Narrow Style from [None] to [No Leader] and set the Text Offset as 1.
Hardware/Software Configuration
Platform: INTL64
OS: windows
OS Version: 764sp1
Product: NX
Application: DRAFTING
Version: V11.0.2
Function: AUTOMATION
Ref: 002-8014670