Delta Larvesta Nature

I saved in front of it and each time I battle it I keep getting an Adamant nature. Is this just really bad luck or??? I have seen the gender change.

UPDATE: Over 15 SR, still adamant. Is it’s nature fixed into Adamant??

Check your first pokemon in the party. You most likely have a synchronizer with the adamant nature.

yep i figured that out afterwards. My mew was adamant. I’m so stupid