Missing slot list in languages other than [en]

[ddppddpp]

I'm trying to add localization for homeassistant_HassRespond for my language (Bulgarian) following the tutorial.
My tests fail with the error hassil.errors.MissingListError: Missing slot list { response }. for the following test item:

tests:
  - sentences:
      - "say I'm a little teapot"
    intent:
      name: HassRespond
      slots:
        response: "I'm a little teapot"
    response: "I'm a little teapot"

I copy-pasted the original english sentence and test into the translated file but the error persists.
I found a similar issue reported in the communities where the OP managed to solve it by changing the slot name (possibly avoiding a scope error), however chaning {response} to {my_response_slot} didn't solve the issue for me.
How do I troubleshoot it further and is it ok to delete the failing test scenario and submit a PR with the remaining translations?

[ddppddpp]

while the issue persists, the localization has been completed by other contributor (missing mentioned test) making it hard to reproduce.