ah that would make sense, im playing on ryujinx
you can try this code:
[shiny pokemon]
040A0000 00F87900 D503201F
040A0000 00F87904 5280002F
(shiny enable code w/o the button modifier)
emulator codes are always on so if you want to disable just restart emulator without the cheat.\
for regular switch users, you can also use it w/ edizon. it kept randomly disabling so i just added the codes w/o the button modifiers
[enable shiny]
040A0000 00F87900 D503201F
040A0000 00F87904 5280002F
[disable shiny]
040A0000 00F87900 B400012F
040A0000 00F87904 B86F6A8F
note: you must disable one then turn on the other. shiny status is determined when pokemon are spawned in the world. so if they are normal, they wont be shiny until they despawn/respawn. vice versa, if they are shiny they won't be normal until respawn/despawn.