The LDAP vendor type is auto-detected and account/pw status attributes are mapped accordingly by the LDAPChai library. There have been updates in the last few years of PWM/LDAPChai for improved OpenLDAP support. Are you using a modern version of PWM? Also, do you have the setting 'Default Settings ⇨ LDAP Vendor Default Settings' set to OpenLDAP?
Additionally, I would recommend not using your old PwmConfiguration.xml file, and starting a new config. Open the old file in a text editor and reconfigure (or copy/paste ) individual settings while evaluating if they are still appropriate for your new environment.