This issue is reproducible on jasperMobile v2.0 Android as well as for jasperMobile v2.1 for iOS.
Changing chart type within a report is wiping off the data, refer the attached screenshot.
STEPS TO REPRODUCE:
1. Login to JasperMobileApp using clarity instance configure with jaspersoft
2. Navigate to library and execute 'Capacity vs Allocation by Resource OBS'
3. Verify that report execute properly and show the data.
4. Try to change the chart type for one of the section (say: Capacity by Employment Type)
NOTE: Tested on iphone4, ipadmini 3 & nexus 4