Bundling and then using the Build Array is not correct. Yuo can see the correct method in the help for an XY Graph below. In order to use the normal XY Grpah, you would have two shif registers. One for the X array and one for the Y. Bundle the two arrays and then wire to the graph.
The other way is to use the Express XY Graph. With that, you can just wire your scalars to the X and Y inputs and set the Reset input to false.
The help does not show bundling the two samples and wiring it to the graph. The help shows exactly what is above. Two arrays bundled together. There is no such indicator as an XY chart. There is a shipping example called XY Chart in which you can make an XY grpah act like a chart. Use that example or one of the two techniques above. Have you tried either of the two I mentioned? If you have, what problems are you still having?
I carefully looked at what you posted about the XY Express graph and I got everything connected correctly, but the graph just shows a constant current for all voltage values. I've attached the VI but won't have access to labview for about a week and a half after I post this.