Lag issue on DB replica

Hi
we are seeing few lag spikes on replica DB , we have seen PQping issue in logs , we are bit clue less is it because of network or process .

[2023-02-24 17:00:07] [DETAIL] PQping() returned “PQPING_NO_RESPONSE”

[2023-02-24 17:00:07] [WARNING] unable to connect to upstream node “node9” (ID: 9)

[2023-02-24 17:00:07] [INFO] checking state of node “node9” (ID: 9), 1 of 6 attempts

[2023-02-24 17:00:07] [NOTICE] node “node9” (ID: 9) has recovered, reconnecting

[2023-02-24 17:00:08] [INFO] connection to node “node9” (ID: 9) succeeded

[2023-02-24 17:00:08] [INFO] original connection is still available

[2023-02-24 17:00:08] [NOTICE] reconnected to upstream node after 0 seconds

[2023-02-24 17:00:12] [WARNING] unable to ping “host= user=repmgr dbname=repmgr connect_timeout=2”

[2023-02-24 17:00:12] [DETAIL] PQping() returned “PQPING_NO_RESPONSE”

[2023-02-24 17:00:12] [WARNING] unable to connect to upstream node “node9” (ID: 9)

[2023-02-24 17:00:12] [INFO] checking state of node “node9” (ID: 9), 1 of 6 attempts

[2023-02-24 17:00:12] [NOTICE] node “node9” (ID: 9) has recovered, reconnecting

[2023-02-24 17:00:12] [INFO] connection to node “node9” (ID: 9) succeeded

[2023-02-24 17:00:12] [INFO] original connection is still available

[2023-02-24 17:00:12] [NOTICE] reconnected to upstream node after 0 seconds

[2023-02-24 17:00:16] [WARNING] unable to ping “host= user=repmgr dbname=repmgr connect_timeout=2”

[2023-02-24 17:00:16] [DETAIL] PQping() returned “PQPING_NO_RESPONSE”

[2023-02-24 17:00:16] [WARNING] unable to connect to upstream node “node9” (ID: 9)

[2023-02-24 17:00:16] [INFO] checking state of node “node9” (ID: 9), 1 of 6 attempts

[2023-02-24 17:00:16] [NOTICE] node “node9” (ID: 9) has recovered, reconnecting

[2023-02-24 17:00:16] [INFO] connection to node “node9” (ID: 9) succeeded

[2023-02-24 17:00:16] [INFO] original connection is still available

[2023-02-24 17:00:16] [NOTICE] reconnected to upstream node after 0 seconds

[2023-02-24 17:00:38] [WARNING] unable to ping “host= user=repmgr dbname=repmgr connect_timeout=2”

[2023-02-24 17:00:38] [DETAIL] PQping() returned “PQPING_NO_RESPONSE”

[2023-02-24 17:00:38] [WARNING] unable to connect to upstream node “node9” (ID: 9)

[2023-02-24 17:00:38] [INFO] checking state of node “node9” (ID: 9), 1 of 6 attempts

[2023-02-24 17:00:39] [NOTICE] node “node9” (ID: 9) has recovered, reconnecting

[2023-02-24 17:00:39] [INFO] connection to node “node9” (ID: 9) succeeded

[2023-02-24 17:00:39] [INFO] original connection is still available

[2023-02-24 17:00:39] [NOTICE] reconnected to upstream node after 0 seconds

Thanks for help