Connect the LDAP accounts, read in with an LDAP sync, with persons. Activate the CP for Search and Create accordingly.
The script LDP_PersonAuto_Mapping_LDAPAccount sets (copied from the ADS script) hard isGroupAccount=True, if the PersonAuto mapping for the LDAP account has found a person. This effectively deactivates the template including IT data mapping (at least initially).
However, the expected result would be: LDAPAccount.isGroupAccount is set via IT Data Mapping.
This is a product defect (34556).
This will be fixed in a future release of the product. If you require this immediately corrected, please contact support for a hotfix referencing the defect ID 34556.