Looks like IF & MB are caught up. For instance they include Ceratiomyxomycetes from the Phytotaxa paper. Nomenclature: [#826861]: IF, MB

So likely what’s in that article falls short of the formal requirements of the ICN.

that while the apparent latest and greatest publication on the higher taxonomy and phylogeny of the slime molds prominently features the use of Eumycetozoa to denote “a monophyletic group formed by the Myxomycetes, Dictyosteliomycetes and Ceratiomyxomycetes,” IF lists it as a nom. inval. under Art. 39.1 (Melbourne), which means it lacks a diagnosis. MB also calls it invalid, but cites 36.1, which is… significantly more complicated. Are both databases behind the times and missing the valid (re)publication in Leontyev at al., 2019 (https://www.biotaxa.org/...), or are there lingering problems? Is it something to do with ICZN vs ICN classification schema?