funny noise after day out

[silverback GT]

Hi all assistance required, just had my first full day out on new crossrunner very impressed  :001:come home smiling from ear to ear lol. parked bike up in garage and when went back in garage half hour later was a funny noise sounds like the inlet of a washing machine letting water in ,open the fuel filler cap and it stops for a minute then starts again has any one had similer

[Notgotone]

Fuel tank venting which is normal

[Lampie]

The tank is heated by the warm engine, that's why it starts again.

[silverback GT]

thought that might be a possibility but thought i would check with the experts cheers guys