"Found uncommitted sync transactions from other instance" when sync replication

Was reproduced on 9ea37ad6 by running while pytest -s -k 2_of_3; do done until the test failed with ConnectionRefusedError and Transaction failed: Unknown: Found uncommitted sync transactions from other instance with id 1 was found in the logs (see transaction-failure-pytest-log.txt).

Instance i3 has failed. This is output of tarantoolctl cat test_2_of_3_writable0/i3/00000000000000000129.xlog (see pytest-tmp.tar.gz):

---
HEADER:
  lsn: 105
  group_id: 1
  type: REPLACE
  timestamp: 1660911306.9895
BODY:
  space_id: 513
  tuple: ['gen', 2]
---
HEADER:
  lsn: 106
  group_id: 1
  type: REPLACE
  timestamp: 1660911307.1358
BODY:
  space_id: 512
  tuple: [0, 14, 2, '', [[1, 1, 8], ['persist_peer', ['i3', '5d7a7353-3e82-30fd-af0d-261436544389',
          2, '127.0.0.1:3303', 'r1', 'e0df68c5-e7f9-395f-86b3-30ad9e1b7b07', 14, 'Online',
          {}]]]]
---
HEADER:
  lsn: 107
  group_id: 1
  type: RAFT
  timestamp: 1660911307.1361
BODY:
  0: 4
---
HEADER:
  lsn: 20
  replica_id: 1
  type: PROMOTE
  timestamp: 1660911307.1369
BODY:
  2: 2
  3: 0
  83: 4
---
HEADER:
  lsn: 21
  replica_id: 1
  type: REPLACE
  timestamp: 1660911307.137
BODY:
  space_id: 515
  tuple: [2]
---
HEADER:
  lsn: 22
  replica_id: 1
  type: CONFIRM
  timestamp: 1660911307.137
BODY:
- null
- 1
- 21
...

Attachments:

• full pytest log: transaction-failure-pytest-log.txt
• /tmp/pytest-of-gmoshkin/pytest-522/test_2_of_3_writable0: pytest-tmp.tar.gz