Continuous Rebalance on Server 7.1.0

When creating a cluster (or upgrading a cluster) to 7.1.0 (currently using build 1169), the Operator reports "failed to rebalance: timeout: unexpected rebalance error", and retries the rebalance (which then fails again, and so on...).

Looking at the server UI, it reports the rebalance as successful, so this could mean the way we check for a rebalance being completed no longer works in 7.1.0?

I've double checked using server versions 6.6.3, 7.0.0, 7.0.1, and 7.0.2 and do not see the issue, so I'm confident this is only present in 7.1.0.