Crash when clicking "Reset to Default" button on the Details Panel for the MaterialAttributeLayers material node.

This crash repros from at least UE 5.3 and up to latest. The following assert is hit:

Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 1067]
Array index out of bounds: 0 into an array of size 0

1. Create a new Material Layer "ML"
2. Create and edit a new Material "M"
2.1. Add a new "MaterialAttributeLayers" node
2.2. On the details panel for the node, locate "Layers – Default Layers – Background – Layer Asset" and set it to "ML"
2.3. Click the "Reset to Default" button to the right of the "Layer Asset" row. Nothing happens.
2.4. Click on the "Reset Element to Default" button next to "Default Layers" – Crash!