list object has no attribute keys

[universe-designer]

turbovault4dbt generates this link model CUST_NHL_CUST_NATION_NHLC.sql

{{ config(materialized='incremental') }}

{%- set yaml_metadata -%}
source_models: 
  stage_customer:
    fk_columns: 
      - 'NATIONKEY_HK'
      - 'CUSTKEY_HK'
    payload:
      - C_NAME
      - C_COMMENT

    rsrc_static: 'Customer'
link_hashkey: HK_CUSTOMER_NATION_L 
foreign_hashkeys: 
  - 'NATIONKEY_HK'
  - 'CUSTKEY_HK'

payload:
    - C_NAME
    - C_COMMENT

{%- endset -%}


{% set metadata_dict = fromyaml(yaml_metadata) %}

{%- set link_hashkey = metadata_dict['link_hashkey'] -%}
{%- set foreign_hashkeys = metadata_dict['foreign_hashkeys'] -%}
{%- set payload = metadata_dict['payload'] -%}
{%- set source_models = metadata_dict['source_models'] -%}

{{ datavault4dbt.nh_link(link_hashkey=metadata_dict.get("link_hashkey"),
                        foreign_hashkeys=metadata_dict.get("foreign_hashkeys"),
                        payload=metadata_dict.get("payload"),
                        source_models=metadata_dict.get("source_models")) }}

dbt run causes the following error:

16:28:26 Compilation Error in model CUST_NHL_CUST_NATION_NHLC (models\raw_vault\CUST_NHL_CUST_NATION_NHLC.sql)
'list object' has no attribute 'keys'

in macro nh_link (macros\tables\nh_link.sql)
called by model CUST_NHL_CUST_NATION_NHLC (models\raw_vault\CUST_NHL_CUST_NATION_NHLC.sql)

If I reduce the code to this. It runs successfully

{{ config(materialized='incremental') }}

{%- set yaml_metadata -%}
source_models: stage_customer

link_hashkey: HK_CUSTOMER_NATION_L 
foreign_hashkeys: 
  - 'NATIONKEY_HK'
  - 'CUSTKEY_HK'

payload:
    - C_NAME
    - C_COMMENT

{%- endset -%}


{% set metadata_dict = fromyaml(yaml_metadata) %}

{%- set link_hashkey = metadata_dict['link_hashkey'] -%}
{%- set foreign_hashkeys = metadata_dict['foreign_hashkeys'] -%}
{%- set payload = metadata_dict['payload'] -%}
{%- set source_models = metadata_dict['source_models'] -%}

{{ datavault4dbt.nh_link(link_hashkey=metadata_dict.get("link_hashkey"),
                        foreign_hashkeys=metadata_dict.get("foreign_hashkeys"),
                        payload=metadata_dict.get("payload"),
                        source_models=metadata_dict.get("source_models")) }}