How to start a new component by uploading a bilingual CSV and avoid "duplicated translation"

[yheuhtozr]

I have a CSV (actually a TSV) transformed from an excel file, which has defining fields as described on: https://docs.weblate.org/en/weblate-5.0.2/formats/csv.html.

I tried adding a new component with the CSV by "Translate document", with the source language and other configs set up accordingly.

It succeeded to create the component, but seemingly always coming with a redundant source language to source language document, and such an alert:

It might be harmless to translation, but can I ask

• how to avoid this error and properly create a component using bilingual CSV
• how should I remove the unneeded translation file for the source language; there seems no way to do it from the UI (the option Organize and remove does not appear on the source language page)