Hi,
Sorry if this is not the right place to report this.
In the last Spanish Wikipedia dump (still in progress):
https://dumps.wikimedia.org/eswiki/20200401/
the "pages-articles" dump is duplicated. I guess, based on the dump from March (and also the previous ones) that they are really two different files, so the filename should reflect it as before.
I am aware there had been recent modifications in the way the multistream dumps are built, so maybe there is some kind of issue there.
Best Regards,