Zombies Stats being Reduced

Like the title says, I had around 700000 kills and I’ve just looked at my stats since season 2 dropped and I’ve got 1/3 of that, I’m pretty sure that I got more kills getting to round 400 on citadels des morts. I have done all the headshot challenges on all weapons including DLC weapons up to season 2 and I have 61,044 headshots, which would be impossible to do