Main Steps to Reproduce

1. click "expand" to open all tree nodes
2. scroll down to the node 50
3. click "collapse" to close all tree nodes
4. scroll down to the last node

Alternative Steps to reproduce

1. scroll down to the last node
2. click "expand" to open all tree nodes
3. click "collapse" to close all tree nodes
4. scroll down to the last node

Current Result

the last several nodes' children node still exist , since node 96 (the node icon shows it's closed but children nodes are not removed)

Expected Result

all children nodes removed

Debug Information

• if I don't do step 2 of main steps, the bug doesn't happen.
• calling tree.invalidate() even produces an expected blank space, cannot be a workaround:
  

Workaround

<custom-attributes org.zkoss.zul.client.rod="false"/>