The main problem is that SSSD shows "Can't contact LDAP server" after sucessfull connection, here is verbose output:
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_id_op_connect_done] (0x4000): caching successful connection after 1 notifies
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [be_run_unconditional_online_cb] (0x4000): List of unconditional online callbacks is empty, nothing to do.
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [be_run_online_cb] (0x0080): Going online. Running callbacks.
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0]
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: end of ldap_result list
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0]
(Thu Jan 9 22:20:42 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_ldap_connect_callback_add] (0x1000): New LDAP connection to [ldap://org.mycompany.com/CN=Configuration,DC=org,DC=mycompany,DC=com] with fd [22].
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_rebind_proc] (0x1000): Successfully bind to [ldap://org.mycompany.com/CN=Configuration,DC=org,DC=mycompany,DC=com].
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_message] (0x4000): Message type: [LDAP_RES_SEARCH_REFERENCE]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_get_generic_ext_add_references] (0x1000): Additional References: ldap://org.mycompany.com/CN=Configuration,DC=org,DC=mycompany,DC=com
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_message] (0x4000): Message type: [LDAP_RES_SEARCH_REFERENCE]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_get_generic_ext_add_references] (0x1000): Additional References: ldap://org.mycompany.com/DC=DomainDnsZones,DC=org,DC=mycompany,DC=com
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_message] (0x4000): Message type: [LDAP_RES_SEARCH_REFERENCE]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_get_generic_ext_add_references] (0x1000): Additional References: ldap://org.mycompany.com/DC=ForestDnsZones,DC=org,DC=mycompany,DC=com
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: end of ldap_result list
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [be_ptask_online_cb] (0x0400): Back end is online
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [be_ptask_enable] (0x0080): Task [SUDO Smart Refresh]: already enabled
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_process_result] (0x0040): ldap_result error: [Can't contact LDAP server]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_handle_release] (0x2000): Trace: sh[0x55f6cc49c710], connected[1], ops[0x55f6cc4f7ad0], ldap[0x55f6cc4eebf0], destructor_lock[0], release_memory[0]
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [remove_connection_callback] (0x4000): Successfully removed connection callback.
(Thu Jan 9 22:20:43 2020) [sssd[be[ORG.DIGITERRA.PRO]]] [sdap_op_destructor] (0x1000): Abandoning operation 3