Replica rebuild completed but unable to start because of missing WAL

In the sentinel, after base backup completed saw the error db won't be able to sync due to missing required wals on master {"db": "bc4ad932", "keeper": "standby1", "requiredWAL": "0000000000000000", "olderMasterWAL": "000004D4000000D6"}.

However, after some time the replica did get built without this error automatically. Wondering is that a bug or something wrong with our set up/config?