I'm using CiviCRM 4.7.29 with Joomla 3.8.3.
We've got a Joomla page connected to a CiviCRM profile definition which allows normal Joomla users to edit there CiviCRM address details and communication preferences. The problem is that the communication preferences checkboxes are never preset to the value stored in the CiviCRM database, the boxes are always unchecked regardless of the underlying stored value. So every time a user edits there address, the stored communication preferences get wiped out, unless they notice and re-tick them manually before clicking save (which rarely happens).
Has anybody else encountered this problem? How would I go about fixing it?