How to import multi-value fields into profile2 using the Migrate module
Make sure you're mapping the field using the right separator, e.g.

$this-&gt;addFieldMapping('field_interests', 'interests')
     -&gt;separator(',');


Then make sure you've the right length in the source field ($this-&gt;map) and your Drupal field support such lengths as well.

If this does not help, increase the length of the destination field by SQL, drush or hook_update.