Kathi Kellenberger notices an oddity with SSRS Mobile Report category charts:
Notice that OrderYear displays decimal points. I switched the dataset in the Series field name property, and found that neither of the columns in the dataset can be used.
Numeric columns cannot be set as a Series name field. To work around this, I modified the dataset, casting OrderYear as a CHAR(4).
That’s not a great situation, but at least there’s a workaround.