This is absolutely normal: the existing seasoning needs to come off entirely, before you re-season your griddle following these steps:

Use a sharp wall paper scraper or spatula or burger flipper and remove all the flakey bits from the surface of the machine. Don’t worry of some patches are left. For as long as they stop flaking away you are ok.

Using a griddle greaser and pads supplied in your starter kit or available on the website, grease the plate and let it smoke gently, at the high heat of 280C. Repeat this 8-10 times, or until a nice golden shine appears on the surface of the griddle. Trick: be VERY patient between layers, i.e: make sure the griddle is nice & dry before applying a new layer. After that, it’s all about constant greasing and cleaning, using both the greaser + pads and the abrasive stone for cleaning at the end of your shift. Please have a look at this video for further instructions.