Extra `strip operator` inserted in template results ?!?!?!

I am trying to create a unified notification script (based on a blueprint from the forum) that i can re-use for all notifications. the script builds the notification payload in several building blocks. when i call the script, i am getting this error Error: expected dict for dictionary value @ data['data']. the section of the script where the error occurs is this:

alias: Send notification
service: '{{ notify_service }}'
  title: '{{ title }}'
  message: '{{ message }}'
  data: '{{ notification_data }}'

the notification_data variable is what was built by the previous building blocks. in the trace is see the data makes it in there correctly, but for some reason it appears that a yaml strip operator (>-) is inserted in the data variable:

 Executed: April 12, 2024 at 2:08:35 PM
Error: expected dict for dictionary value @ data['data']

  domain: notify
  service: mobile_app_sebs_devices
    title: ''
    message: THE MESSAGE
    data: >-
      {'subtitle': Undefined, 'push':
      {'interruption-level': Undefined}, 'actions': [{'enabled': True, 'action':
      '', 'title': 'TEST', 'icon': 'sfsymbols:field_opt_1_icon', 'destructive':
      'field_opt_1_destructive', 'authenticationRequired':
      'field_opt_1_authentication_required', 'uri': 'field_opt_1_uri'},
      {'enabled': True, 'action': '', 'title': 'TEST2', 'icon':
      'sfsymbols:field_opt_2_icon', 'destructive': 'field_opt_2_destructive',
      'authenticationRequired': 'field_opt_2_authentication_required', 'uri':
      'field_opt_2_uri'}], 'tag': Undefined}
  target: {}
running_script: false

the previous step where the notification_data is built also adds the strip operator to the variable. Here is the yaml for that section:

  options: |- 
    {{ [option_one, option_two, option_three] | selectattr('enabled') | list }}
  expect_response: |-
    {{ enable_timeout or option_one_enabled or option_two_enabled or
    option_three_enabled }}
  notification_data: |-
    {% set payload = namespace(data={ 'apple_device': true }) %}
    {% set push = namespace(d={}) %}
    {% set payload.data = dict( payload.data, **{ 'subtitle': subtitle }) %}
    {% set push.d = dict(push.d, **{ 'interruption-level': interruption_level })%}
    {% if notification_link | length %}
    {% endif %}
    {% if attachment_type == 'camera_entity' %}
      {% set payload.data = dict(payload.data, **{ 'entity_id': attachment_camera_entity }) %}
    {% endif %}
    {% set payload.data = dict(payload.data, **{ 'push': push.d }) %}
    {% set payload.data = dict(payload.data, **{'actions': options }) %}
    {% set payload.data = dict(payload.data, **{'tag':tag }) %}
    {% if group|length %}
      {% set payload.data = dict(payload.data, **{'group': group }) %}
    {% endif %}
    {{ payload.data }}
alias: Setup Mobile Payload

I’ve tested the service call with the contents of the data variable and it works as expected, just not sure how to remove the strip operator >-. Anyone have any hints?

EDIT: edited the title for clarity…

if i copy the body of the data object and paste it into a service call to the same notify.mobile_app_sebs_devices, it works without an issue

updated the title to add clarity to the error