Indicator reads a number, Wire attached to it reads NaN

I have  run into a strange problem that I have not been able to figure out yet - despite multiple searches, code deletions and rebuilding and much testing.

I'm supporting an older system, so this is in LabVIEW RT 8.2.1 on a PXI.

I have a sub-VI that generates a number and I can see that number in an indicator on the front panel. When my VI wires to that indicator on the subVI, I am seeing NaN. 

Here it is showing the indicator and the probe on the wire from the connector. Yes, the indicator is wired to the connector panel (I have rewired it a couple of times now to test).

And here are two probes: One inside the sub-VI, the other immediately outside the VI:

Looks very strange to me. Since when does a connector change a value?

Unfortunately, I can not reproduce this with a simpler VI and I can not include the proprietary code.

I would appreciate any and all suggestions on how to get around this problem.

     Rob