API response bodies are empty when using active_model_serializers

[dnlsandiego]

I have a Rails 5 app in API mode using this gem and active_model_serializers. devise_token_auth's controllers renders plain hashes as responses but neither of all the 3 adapters from active_model_serializers seem to be able to render the hashes to JSON.

Versions:
Rails 5. (--api mode)
active_model_serializers: 0.10.2
devise_token_auth: 0.1.37 (tried 0.1.39, still the same)

Expected behavior vs actual behavior

curl -i -X DELETE http://localhost:3000/v1/auth/sign_out

Expected response body:
{ success: false, errors: ['User was not found or was not logged in.'] }

Actual response (with the default active_model_serializer adapter):
{}

With the active_model_serializer :json_api adapter:
NoMethodError (undefined method read_attribute_for_serialization' for {:errors=>["User was not found or was not logged in."]}:Hash)`

With the active_model_serializer :json adapter:
NoMethodError (undefined methodmodel_name' for Hash:Class):`

I filled an issue over there rails-api/active_model_serializers#1893 as well. I've read some other issues here that imply most devise_token_auth users are using active_model_serializers as well. What is the proper configuration (if any) between both gems?

I can provide a repo that reproduces this issue if needed.

[dnlsandiego]

@lynndylanhurley Sorry to specifically tag you on this but I've been stuck on this issue for about almost a week. Any idea on what would be causing this?