Burrow does not detect consumer groups

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We have a nightly run where we (in the following order)
1. install and run kafka 1.0.0
2. install and run burrow
3. creating topics in kafka
then we run our apps (and some tests) which create consumer groups which commit to kafka. The topic offsets and consumer group lags are periodically sent from burrow to grafana.
In the morning when I check grafana it shows no info about consumer groups (the topic offsets are available). When I ask burrow manually via rest api for consumer groups it returns an empty list, although kafka's kafka-consumer-groups.sh script returns all available consumer groups (and lags) created by our apps. After restarting burrow it starts to return consumer groups too (not only topics) which appear in grafana then. What could be the problem here? Should we install and start burrow as last step in our nightly run?

Start by reproducing the nightly sequence of Kafka 1.0.0, Burrow, topic creation, and app consumer-group commits. Compare Burrow's REST API response with kafka-consumer-groups.sh before and after restarting Burrow, and verify that consumer-group data reaches Grafana without a restart.

Written by the indexing model from the issue text.