When using a newly created Multi-Select field on Tablet (iPad / Android) only one selection option can be selected at a time.
The multi-select field is working like a single select field on a tablet device.
Resolution / Workaround:
The workaround for this issue is to use the Desktop UI instead of the Tablet UI. This can be Changed in MyCRM -> Preferences and set the Default Tablet Version to Desktop version.
This issue is not an issue in Sage CRM 7.3 GA.
It was an issue in Sage CRM 7.2d
This is not affecting the iPhone / Mobile (Android) UI screens and multi-select fields are working as expected.