mobile and pager ldap attributes are visible in the SOGo UI, but only telephoneNumber is visible via EAS GAL:

Given the following user source:
SOGoUserSources = (
{
type = ldap;
CNFieldName = cn;
UIDFieldName = sAMAccountName;
...
id = public;
isAddressBook = YES;
SearchFieldNames = (displayName, mail, sAMaccountName);
},

My user has the following attributes set:

telephoneNumber: +390731**
mobile: +393***
pager: 322

On the Web Interface I see all the attributes:
Work:
+390731**
Mobile:
+3933***
Pager:
322

But on my Android device with Activesync if I search for my username I can only see the telephoneNumber attribute