This is not a regression. Tested in //UE5/Release-5.0 CL20979098

The array for Vector Parameters isn't getting populated when called from a Dynamic Material Instance.

Steps to Reproduce
  1. Create or open any project
  2. Create a new material named M_Test
    1. Add 1 or more Vector Parameter nodes then connect it to Base Color
    2. Compile, save, and close the material
  3. Create a new Blueprint Actor named BP_DMI
    1. Add a Cube Component
    2. In the Event Graph off of Event Begin Play create a 'Create Dynamic Material Instances(Cube)'
    3. Set the Source Material to M_Test
    4. Off the Return Value create a 'Get Vector Parameter Values'
    5. Off the Array of that node create a 'Length' node
    6. Connect the Length node's output to a 'Print String' node
    7. Connect up the execution pins
    8. Compile, save, and close the Blueprint
  4. Place BP_DMI in the scene
  5. Play in Editor
  6. Observe the value printed to the string

Expected Results:
The length of the array is equal to the number of Vector Parameters in the Material.

Actual Results:
The length returns 0. The array isn't populated.

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ComponentUE - Rendering Architecture - Materials
Affects Versions5.1
Target Fix5.5
CreatedJan 3, 2023
UpdatedJan 24, 2024
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