Just checked the mirrors.

• The Academic Computer Club, Umeå University mirror apparently only mirrors the last two good dumps, not the last five:  https://ftp.acc.umu.se/mirror/wikimedia.org/dumps/enwiki/
• The Bytemark mirror seems to have stopped mirroring in May 2020: https://wikimedia.bytemark.co.uk/enwiki/ 
• The C3SL mirror seems to have stopped mirroring in November 2019: http://wikipedia.c3sl.ufpr.br/enwiki/
• The Free Mirror Project mirror seems to work fine.
  
• The Your.org mirror seems to work fine.
•  https://wikimedia.mirror.us.dev/ seems to work fine.
  

Maybe the hosters of the failing mirrors should be contacted or the list updated?

Best regards,

Count Count