Bugreport | Logical replication PostgreSQL 12 | Error after disable / enable replication

Hello PostgreSQL Team,

I encountered a problem with logical replication in PostgreSQL 12.

After disable/enable of a subscription I get error messages

ERROR: could not start WAL streaming: FEHLER: Replikations-Slot »mysub«
ist aktiv für PID 21192

Steps to reproduce

==================

Used PostgreSQL Versions

------------------------

Publisher:

Windows 7 / postgresql-12.4-1-windows-x64

Subscriber

Debian 9.13 / 12.4-1.pgdg90+1

Step to reproduce

-----------------

Publisher:

CREATE PUBLICATION mypub FOR TABLE

data.table-1

data.table-2

data.table-3

data.table-4

data.table-5

data.table-6

data.table-7

data.table-8;

Subscriber

CREATE SUBSCRIPTION mysub

CONNECTION 'dbname=... host=... port=5433 user=postgres password=...'

PUBLICATION mypub

WITH (copy_data = false);

;

ALTER SUBSCRIPTION "mysub" disable;

wait several minutes

ALTER SUBSCRIPTION "mysub" enable;

Logs

2020-09-30 19:51:14.407 CEST [15578] 00000 LOG: logical replication
apply worker for subscription "mysub" has started

2020-09-30 20:00:54.914 CEST [15578] 00000 LOG: logical replication
apply worker for subscription "mysub" will stop because the subscription was
disabled

2020-09-30 20:11:34.265 CEST [20198] 00000 LOG: logical replication
apply worker for subscription "mysub" has started

2020-09-30 20:11:34.301 CEST [20198] XX000 ERROR: could not start
WAL streaming: FEHLER: Replikations-Slot »mysub« ist aktiv für PID 21192

2020-09-30 20:11:34.302 CEST [15428] 00000 LOG: background worker
"logical replication worker" (PID 20198) exited with exit code 1

2020-09-30 20:11:39.309 CEST [20212] 00000 LOG: logical replication
apply worker for subscription "mysub" has started

2020-09-30 20:11:39.352 CEST [20212] XX000 ERROR: could not start
WAL streaming: FEHLER: Replikations-Slot »mysub« ist aktiv für PID 21192

2020-09-30 20:11:39.354 CEST [15428] 00000 LOG: background worker
"logical replication worker" (PID 20212) exited with exit code 1

2020-09-30 20:11:44.357 CEST [20222] 00000 LOG: logical replication
apply worker for subscription "mysub" has started

2020-09-30 20:11:44.396 CEST [20222] XX000 ERROR: could not start
WAL streaming: FEHLER: Replikations-Slot »mysub« ist aktiv für PID 21192

2020-09-30 20:11:44.398 CEST [15428] 00000 LOG: background worker
"logical replication worker" (PID 20222) exited with exit code 1

2020-09-30 20:11:49.402 CEST [20225] 00000 LOG: logical replication
apply worker for subscription "mysub" has started

2020-09-30 20:11:49.452 CEST [20225] XX000 ERROR: could not start
WAL streaming: FEHLER: Replikations-Slot »mysub« ist aktiv für PID 21192

2020-09-30 20:11:49.453 CEST [15428] 00000 LOG: background worker
"logical replication worker" (PID 20225) exited with exit code 1

I set up this configuration a few months ago with an earlier version and it
worked.

Best regards,

Michael