If you have an FIFO read node in an RT subVI with a SGL type
And enter the configuration reference dialog
When you come out, the wire to your subVI will be broken and your FIFO read will turn into a FXP type (notice color change)
FYI this is LV2016
I'm guessing it's uncommon to use that dialog?
Thank you for bringing this behavior up. I did some investigation and found that this also happens on LabVIEW 2015 SP1. Interestingly enough, it does not matter if it is connected or not, once you configure the refnum, if you go into the configuration dialog box again, it makes the SGL into FXP. However, if you go into the dialog box again and import again, then it goes back to SGL. I will look into this more and let you know what I find out.
Thank you for bringing up this incorrect behavior. We have filed CAR 608514 for this.