for some reason. adding a new mod then booting up a world that did not originally have that mod causes ALL foxes to have the same texture. (new and pre exisiting)

i found this out by adding https://www.curseforge.com/minecraft/mc-mods/slashblade/files/3039993

before

after

log, might have somthing usefull for you.
latest.log

(edit) after a while they get their textures back

(edit... again) after server restart their textures are all buged again.