Rebalance button is not clickable after delete travel-sample bucket and add a node

Step to reproduce

• Create a node with Couchbase server 6.0.2-2384 with kv service only (225).
• Add another 6.0.2-2384 node (224) with services kv, index, n1ql and fts (not rebalance yet)
• Create travel-sample bucket on setting page.
• When travel-sample bucket ready but not load sample yet, delete travel-sample bucket.
• Cancel add node 224.
• Add node 224 with services kv, index, n1ql and fts again back to cluster (225)
• Rebalance button is disable and see warning "Warning: Rebalance is not available until data loading is completed."
• Wait for 10 minutes and reload page, rebalance button is still disable.