I opened the "Box data report" on my Ultra Sun save and at the bottom of the list I found some hacked pokemon, specifically saved in the "Resort-XX" location.
This is probably due to the GTS being filled with hackers witch caused my game to crash yesterday.
Anyways I found a way to access this location in block data -> Resort save -> PKM[] Array , and when I try to remove them it gives the error: "Property value is not valid: Resort Count".
My issue is that I cannot find anything about "Resort count" in the options.
I even tried to set the "Species" value to 0, but with no effect.