Unfortunately, I was wrong. It didn’t work again for me (not for long, anyway).
However, I learnt that generated pages having the same fingerprint might affect deploys.
So after varying the generated pages by replacing manually a placeholder,
it appears to be ok for me now.
More intuitive solutions are very welcome if you know some with regard to Nuxt.js 2 
Thank you @fool, one of your previous replies helped me with this one: