Spectral Analysis Delegates Do Not Behave As Expected If 3 Or More Are Attached To The Same Submix

When attaching 3 or more Spectral Analysis Delegates to the same Submix, some delegates start returning only zero values. If this is a known limitation of Spectral Analysis Delegates, we should probably note this in the tooltips somewhere.

• Create a Submix asset (right-click on the Content Browser and go to Sounds->Mix->Submix)
•  Place a Sound Wave in your level, and ensure it is set to auto-play
• Go to the Sound Wave's settings, and set its Base Submix to the Submix you created in Step 1
• In your Level Blueprint, create a Sound Submix Object Reference variable, and make it's default value the Submix you created in Step 1
• Add the function Add Spectral Analysis Delegate to your Level Blueprint, attach it to BeginPlay, and make the Submix variable it's target
• Drag off of the In Band Settings field on the Add Spectral Analysis Delegate and promote it to a variable. Compile the Blueprint, then add an entry to the variable's default value
• Drag off the On Submix Spectral Analysis BP field on the Add Spectral Analysis Delegate, and select "Add Custom Event"
• On the new Custom Event, put the magnitudes through a For Each loop and print each one. It may be worth making the text a distinct color to distinguish this from the output of other spectral analysis delegates
• Add a new Spectral Analysis Delegate and repeat all of the above steps for the new Delegate.
• Play the game, and notice that both Spectral Analysis Delegates are consistently returning non-zero values
• Repeat the above steps for yet another Spectral Analysis Delegate, and play the game

Expected Results:

• The outputs of the Spectral Analysis Delegates should have reasonable values

Actual Result:

• The output of the first Spectral Analysis Delegate is now a solid stream of zeros, despite measuring the same frequency it was before the third delegate was added