UK signed a deal for the Brexit. Now UK doesn't want to honor its part of the deal, aka give european (and french) fishermen the authorization required by the deal...

Moreover, Jersey limited the parts of the fishing zone to be less than what the Brexit deal was negociated...

So... how do you deal with a country that signed a treaty 5 month ago and doesn't want to respect it ???? Jersey is just "another brick in the wall"