But I guess as you are confirming that the UK forum works for the INT1 server, there will be users that already used some of those codes, which on the other hand would mean additional effort in cross-checking who exactly already did so when trying to fix the codes from the US forum.
And although I would much rather claim the US forum code for Dec 1 , I am afraid Playata will decide to advise INT1 users to just continue using the UK forum instead to avoid the above mentioned additional effort
Actually, to also address all the confusion around the advent calendar for INT1 users, I would not blame Playata for allowing to claime both UK and US codes until they have fixed the issue