Do you have any idea why an WHEN-TREE-NODE-EXPANDED trigger fails to fire in my form ?
My form has a tree with an item level WHEN-TREE-NODE-EXPANDED trigger.
Node 2.1 is initially collapsed.

The trigger usually fires when the user clicks on the NODE 2.1 (+) but it fails to fire about 1 in 20 time when testing. The node expands, but the trigger does not fire
There are no other WHEN-TREE-NODE-EXPANDED triggers at the form or block level
The test case is simple and reproducible in the application so I am very confident that the trigger is not firing. ... open the form, navigate to a tab that has the tree control on it, the tree will be populated with data. click on the (+) link to expand one of the nodes in the tree
Environment Forms 11.1.2.2.0, Java 8 update 66, client Windows 10 v1809
Any ideas on why WHEN-TREE-NODE-EXPANDED it fails to fire every time ?