I have had the exact same issue on my 2020 N 200, TWICE now. I am on my 3rd coolant reservoir. Nautique in Orlando told me to contact PCM. My dealer wants it in for servicing, but that is weeks out each time and not worth it for a 60 dollar part I can swap myself. This time I am going to try and put some thick washers under the mounts to raise it up a quarter inch or so to try and prevent any contact with the manifold which seems to be causing the small crack to form from slight vibrations against the hot manifold. Not a huge deal in the grand scheme of things but annoying to have to deal with, I don't want to have to do this every 2 years.