The main problem no longer seems to be the achievement being bugged; it's getting the 6 minutes kill at this point. I didn't finish the achievement back then and missed the first day of the re-release. I could theoretically get the achievement, but it seems impossible.
Public instances never get it even during peak hours. The only option then seems to be private instances, which are pain to organise and still often miss the achievement by at least minute, even when advertised as food+meta builds only.