Edit: as hand-luggage
Edit: as hand-luggage
Odd, as in the US, there is no limit if in your checked baggage if below 24% ABV, and 5 liters if 24% - 70% (carry on has much stricter limits [3.4oz or less that can fit comfortably in one quart-sized, clear, zip-top bag], but is still permitted).
https://www.tsa.gov/blog/2019/06/21/tsa-travel-tip-traveling...
You're not allowed to open the bag on the flight, obviously.
The duty free is inside the secure area, you've already passed security.
they were correct, the international arrivals required another bag check to enter the domestic part of the airport, that had the stringent TSA rules (after you went through customs and collected your luggage, before you could drop your luggage off again for your next flight).
so, it appears to be airport by airport when traveling to the US.
Not doubting your experience because policies change, but every US airport I've flown into has customs and immigration after an international flight, and after re-checking in your hold baggage if you have any, virtually all then route you to the normal TSA check before a domestic flight unless there's an airside transfer option directly to the gates.
at this point, you could no longer have anything in your checked baggage that could not go through standard TSA security, as you were already inside the secured area. some airlines (Alaska, for instance) allowed you to check your baggage PAST that security area, but you still had to make it past.
since you had already picked up your checked baggage, and no longer could get to any connecting flights without either exiting the airport completely (far away from other flights), or going through security again with your luggage to continue to the monorail, you were pretty much screwed.
editing to add: there were a lot of very unhappy people who had their airline provided or purchased past security water bottles being taken away before they could continue to their domestic flights. I have no clue exactly how far I would have had to walk outside of security to get to the domestic terminal, but my flight was so soon that I would never have chanced it.
double editing to add that I've flown international through other airports and never had that type of experience other than through Seattle.
triple editing to note that even SEATAC seemed to think this was a mess and the new international arrivals terminal is due to open "soon".