BUG #17438: Logical replication hangs on master after huge DB load

The following bug has been logged on the website:

Bug reference: 17438
Logged by: Sergey Belyashov
Email address: sergey(dot)belyashov(at)gmail(dot)com
PostgreSQL version: 14.2
Operating system: Debian 11, GNU/Linux x86_64
Description:

Master DB has few tables: A (few inserts per second, about 200 updates per
second, ~100 deletes each 5 minutes), B (~100 inserts each 5 minutes), C
(~200 inserts and ~200 updates per second). B and C are large partitioned by
range tables (36 and 12 partitions). A is small table about 10K entries
(often updates). Table A has publications for inserts and deletes. Table B
has publication for all operations except truncate via root.

I do some maintenance work. I stop production load on DB and do some high
load operations with table C (for example: "insert into D select * from C").
After completion replications for A and B freezes and loads CPU for 50-99%
without actual data transmission. I try to disable/enable/refresh
subscription, but no effect. I try to restart master - no result. Only
drop/create of subscriptions helps me.

Publisher logs many messages like following:
2022-03-14 19:57:02.907 MSK [1771976] user(at)DB ERROR: replication slot
"A_sub" is active for PID 1766849
2022-03-14 19:57:02.907 MSK [1771976] user(at)DB STATEMENT: START_REPLICATION
SLOT "A_sub" LOGICAL 28C/60150F50 (proto_version '2', publication_names
'"A_pub"')
2022-03-14 19:57:02.909 MSK [1771977] user(at)DB ERROR: replication slot
"B_sub" is active for PID 1766828
2022-03-14 19:57:02.909 MSK [1771977] user(at)DB STATEMENT: START_REPLICATION
SLOT "B_sub" LOGICAL 28C/AE2B7D8 (proto_version '2',
publication_names '"B_pub"')

Subscriber logs many messages like following:
2022-03-14 19:56:52.709 MSK [3266082] LOG: logical replication apply worker
for subscription "B_sub" has started
2022-03-14 19:56:52.710 MSK [993] LOG: background worker "logical
replication worker" (PID 3266080) exited with exit code 1
2022-03-14 19:56:52.814 MSK [3266081] ERROR: could not start WAL streaming:
ERROR: replication slot "A_sub" is active for PID 1766849
2022-03-14 19:56:52.815 MSK [993] LOG: background worker "logical
replication worker" (PID 3266081) exited with exit code 1
2022-03-14 19:56:52.818 MSK [3266082] ERROR: could not start WAL streaming:
ERROR: replication slot "B_sub" is active for PID 1766828
2022-03-14 19:56:52.819 MSK [993] LOG: background worker "logical
replication worker" (PID 3266082) exited with exit code 1