Expression Binding -- Error when binding to a property on different component

I believe I have found a bug using Perspective 8.0.13.

I am attempting to compare two values (which are being Exported from Embedded Views):

The error is clearly coming from the …/30D_Avg value as noted by a regular property binding to it:

I’m not sure if there’s a different format I can be writing the properties in. The displayed format is what the Browse Properties selector returns.