Fuel smell - 2 days into ownership

Got my superb estate 2 days ago

Filled up with £50 on weds

Came home could smell fuel

Same again yesterday

Got home from a trip and could smell fuel

Noticed a wet patch on my fuel tank

Went to the garage today

They inspected it and said there is no active leaks

They had it in a garage with the doors shut and running and couldn’t smell anything

But when I’ve had it back this evening

Absolutely stinks

Soon as you open the fuel flap it’s as if you have your head in the tank

It’s so strong

Did a few searches and there’s tons of info online

One think I don’t know Is

There seems to be a gap between the plastic and the fuel filler neck

Is this normal?

Also just pushed the rubber boot back down, would this cause the fuel smell? Or can it be pushed up with tank pressure? Possibly from a faulty evap or n80?