Predictive Cash Advanced Predictions Failing Data Transformation

Summary:

I am using Advance Predictions and getting errors on a simple setup. I am trying to use two banks as our driver and put the prediction into the OEP_Any Bank in Predictive Cash Forecasting. Below is the error and screenshots of the data mappings. It isn't a calendar issue as the calendar is working on other predictions. Why can two bank accounts not be used as drivers for the OEP_Any Bank output prediction?

Transforming historical data for output variable could not be completed, check if the mapping is correct, data is present and calendar is configured correctly