The tank on my 2013 2.2 was doing the same thing since new. The problem is with the tank, not the lid. Apparently there is an occasional hiccup in the tank production that leaves a very slight notch in the top of the neck - hence why the lid cannot achieve a seal when hot/under pressure.
I had the tank & lid replaced under warranty and all is good now 
Cheers,
Pete
1963 S2A 88 113-300 6 RAR, VTF, Vietnam.
1989 Perentie FFR 49-290 2 Sig Regt.
1989 Perentie FFR 49-390 1 MP BN.
1990 Perentie GS 50-087 5 RAR.
2013 Defender 110 Wagon, 'Snowy'.
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