I reviewed some of the initial discussion about this same issue which lead to this fix in version 2.4.26, "Fixed libldap ASYNC TLS setup (ITS#6828)", and looked at the code that Ian Puleston suggested should be fixed in ldap_int_open_connection. This routine does have the code to do what was need for TSL to work but was not called since it received an error code of -2 not 0. The -2 simply indicated that this was an asynchronous call. I changed the test to call the TSL setup if the return code was either 0 or -2. This fixes my issue. Here is my patch.

--- openldap-2.4.47/libraries/libldap/open.c    2018-12-19 10:57:06.000000000 -0500 +++ openldap-2.4.47.mod/libraries/libldap/open.c    2019-01-26 18:24:48.000000000 -0500 @@ -440,7 +440,7 @@  #endif

#ifdef HAVE_TLS -    if (rc == 0 && ( ld->ld_options.ldo_tls_mode == LDAP_OPT_X_TLS_HARD || +    if ((rc == 0 || rc == -2) && ( ld->ld_options.ldo_tls_mode == LDAP_OPT_X_TLS_HARD ||          strcmp( srv->lud_scheme, "ldaps" ) == 0 ))      {          ++conn->lconn_refcnt;    /* avoid premature free */

Thanks, Vernon