The translation dashboard in Content translation shows the percentage of progress for in-progress translations. When hovering over, a tooltip shows the percentage of the source article that has been translated, and the percentage of machine translation used. The percentage of machine translation used currently is not reliable.

If you start a translation, add 2 paragraphs with machine translation, delete one word of each paragraph, and go back to the dashboard. The tooltip shows 0% of machine translation, which should not be the case:

I repeated the test without deleting any content, and it was correctly showing 100% of MT, which is the expected result.

The issue seems related to the old way of calculating the percentage of machine translation, and should be updated to be aligned with the approach we use in T221930.