Summary:

When using a newly created Multi-Select field on Tablet (iPad / Android) only one selection option can be selected at a time.

Symptoms:

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. 

Status:

This issue is not an issue in Sage CRM 7.3 GA.
It was an issue in Sage CRM 7.2d

More information:

This is not affecting the iPhone / Mobile (Android) UI screens and multi-select fields are working as expected.