burrow lags in generating consumer/topic list

[deathyard]

Im facing an issue when trying to get all consumer groups and topics under a kafka cluster through the HTTP endpoints:-
/v3/kafka/(cluster)/consumer and /v3/kafka/(cluster)/consumer/(group)
Everytime burrow is restarted (using kill -1 and running the process again), the output of the above endpoints will initially display empty lists and then slowly start to update with actual amount of consumers/topics over the period of next 5-10 seconds.

Is this intended behaviour or burrow can get incomplete data from kafka clusters ?