Text to Speech does not work in Play in Editor

This is not a regression as the TTS plugin isn't available in 4.27.2.

Text to Speech does not work in Play in Editor, but does work in Stand Alone.
A warning is thrown:

LogSlateStyle: Warning: Unable to find Slate Widget Style 'New Channel Id'. Using FToolbarStyle defaults instead.

Changing the Channel ID still results in a warning.

Text To Speech Quickstart

• See attached Screenshots for setting up the Widget Blueprint Graph, and Level Blueprint

1. Create or open any project
2. Enable the Text to Speech plugin then restart the editor
3. Create and open a new Widget Blueprint based on User Widget name 'WBP_TTS'
   1. Select WBP_TTS in the Hierarchy panel then enable 'Is Focusable' in the Details panel
   2. Add a Canvas Panel and a Button to the widget
   3. Select the Button then select 'On Clicked' event under Events in the Details panel
   4. Create a 'Text to Speech System Engine Subsystem' node
   5. Off of the TTS node create an 'Add Default Channel', 'Activate Channel', and 'Speak Channel' node with execution pins connected in that order
      1. Connect the TTS node to the 'Target' input pin of all 3 nodes if it isn't
      2. Right click the 'Channel ID' input pin of any of the nodes then promote it to a variable
      3. Connect that Variable to the 'Channel ID' input pin of all 3 nodes
      4. Create a 'Format Text' node then populate it with some text
      5. Connect that node to the 'String to Speak' input pin of the 'Speak on Channel' node
   6. Compile, save, and close the Widget
4. Open the Level Blueprint to add the widget to the Viewport, enable the cursor, and set the input mode
   1. Create an 'Event BeginPlay' node
   2. From that node create a 'Create Widget' node
      1. Set the Class to the 'WBP_TTS'
      2. Get a reference to the 'Get Player Controller' node then connect it to the 'Owning Player' input pin
   3. Create an 'Add to Viewport' node
   4. Connect the 'Return Value' of the 'Create...' node to the 'Target' input of the 'Add to Viewport' node
   5. Create 'Set Input Mode UI Only' node
      1. Connect the Player Controller reference to the Player Controller input
      2. Connect the Return Value output of the 'Create...' node to the 'In Widget to Focus' node
   6. Drag off the Player Controller reference then create a 'Set Show Mouse Cursor' node
   7. Set 'Show Mouse Cursor' to true
   8. Compile, save, and close the Level Blueprint
5. Play in Editor
6. Click the Button on screen and listen

Expected Results:
The text inputted into the 'Speak on Channel' plays over audio.

Actual Results:
No Text to Speech sound is heard. A warning is thrown in the Output Log:

LogSlateStyle: Warning: Unable to find Slate Widget Style 'New Channel Id'. Using FToolbarStyle defaults instead.