ERROR: could not open relation with OID 149416084

[banlex73]

Hello
We faced an issue today:
ERROR: could not open relation with OID 149416084
From postgres log:
2021-11-03 01:22:19.505 UTC [31907] (user=xmcdcuser) (db=na5) (rhost=10.139.204.7) (app=auditConsumer) [vxid:843/0 txid:0] [idle] ERROR: could not open relation with OID 149416084
2021-11-03 01:22:19.505 UTC [31907] (user=xmcdcuser) (db=na5) (rhost=10.139.204.7) (app=auditConsumer) [vxid:843/0 txid:0] [idle] CONTEXT: slot "cdc_na5", output plugin "wal2json", in the change callback, associated LSN 4756/A5147B48
2021-11-03 01:22:19.505 UTC [31907] (user=xmcdcuser) (db=na5) (rhost=10.139.204.7) (app=auditConsumer) [vxid:843/0 txid:0] [idle] STATEMENT: START_REPLICATION SLOT cdc_na5 LOGICAL 4749/EC77340 ("include-typmod" 'false', "include-types" 'false', "include-schemas" 'false', "include-not-null" 'false', "add-tables" '.event_property_hierarchy_values,.drngss,.persons_func,.num_page_dvc_dtl,.gen_dvc_dtl,.evs_message,.live_ntfn,.cust_attr_cat,.role_perm_grants,.org_dvc_names,.role,.response_choices,.tmp_rpmt,.phone_creds,.person_cust_values,.application,.attrs,.event_property_values,.im_dvc_dtl,.cust_flds,.oncall_reminders_configured_start_times,.voc_dvc_dtl,.org_svc_provs,.email_dvc_dtl,.comm_values,.org_tz,.attr_cat_join,.comm,.date_rng,.tm_rotation,.org_holidays,.dvc,.person_attrs,.release_version,.fax_dvc_dtl,.person_ntfn,.message_panel_recipient,.dvc_ntfn,.response_choices_transl,.grp_ntfn,.date_holiday_cntner,.tz,.ntfn_responses,.cdc_audits,.perms,.runtime_response_choices,.txt_phone_dvc_dtl,.drs_excludes,.gcm_push_dvc_dtl,.tm_ntfn,.attr_cat,.ntfn,.event_property_list_values,.tm,.oncall_reminders,.grp_tf,.event_property_text_values,.oncall_reminders_configured_devices,.voice_ivr_dvc_dtl,.role_func,.txt_page_dvc_dtl,.org_languages,.comm_flds,.addresses,.ev_annotation,.web_creds,.date_rules,.sns,.recipient_ntfn,.tm_mbrships,.sites,.drss,.languages,.ev_metadata,.site_holidays,.grp,.tm_escalation,.persons,.org_func_perms,.message_panel,.date_rpt_patterns,.org_func,.apple_push_dvc_dtl,.evs,.conferences,.recipients,.runtime_response_choices_transl,.drs_includes,*.drngs_rng', "include-timestamp" 'true', "include-lsn" 'true', "include-type-oids" 'false', "pretty-print" 'false', "write-in-chunks" 'true', "include-xids" 'true')

Checked what was
select relname from pg_class where oid=149416084;

idx_comm3

What might be wrong:
we started reindex index concurrently public.idx_comm3 at 2021-11-03 01:21:59
and reindex process was blocked by another transaction, reindex successfully finished at 2021-11-03 01:23:15
But since 2021-11-03 01:22:19 wal2json tried to read that index ( OID 149416084) but in fact, index wasn't ready till 2021-11-03 01:23:15

How we fixed it:
ran pg_replication_slot_advance

It looks like a bug to me...

PS: we are on

wal2json=2.4.1
Postgres 12.8
OS CentOS 7