Einstein Bot Dynamic Choices from Flow (Text Collection) going to Error Handler instead of displaying options

Hi everyone,

I’m trying to display a list of Cases in an Einstein Bot using a Flow as a dynamic data source, but I’m running into an issue where the bot goes straight to the error handler instead of showing the options.

What I’m trying to achieve

I want the bot to:

•  Call a Flow 
•  Retrieve a list of Cases for a Contact. (limit to 5)
•  Display those Cases as selectable options in a Question step 

Current setup

Flow (Autolaunched): I saw and article that the returned list must be in string.

•  Input: contact_id (Text) 
•  Get Records: Case (filtered by Contact) 
•  Loop through Cases 
•  Add Case.Subject to a Text Collection variable called subject
•  Output: 
  • subject (Text Collection, available for output) 

Example Flow output (from logs) at the end. 

Now I tried this, and also tried to retrieve a list of objects instead of strings, then assign to variable where dynamic question would use. 

Either of both aproaches, do get the info I need, the list of cases subjects and or Id populate in performance tab, however: 

1- When used object instead of string list, I would get the objects values I need but list would need a formula to show every object in list. 

2- When used string list, performance tab shows data but it would not populate list to customer. 

Kinda in a limbo now. 

{
  "subject": [
    "Test subject",
    "Test case creation",
    "My watch is not syncing",
    "WhatsApp Support Request"
  ]
}