Even though a minority of authors consider myxomycetes as an ambiregnal group or being governed by ICZN it is nowadays mostly recognized being ruled by ICN.
More information is available in cited source of this swap (Ronikier et Halamaski, 2018).
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.