It's also orthogonal to the question of how they get the money. The US entity can get paid, the question is whether the US entity is able to pay Flipper employees.
I suspect sanctions and international finance laws are a bit more complex than that. It could be that a US legal entity that is fronting for a sanctioned country can indeed be blocked from receiving money, but you'd have to get a quorum of international finance lawyers to hammer out an agreement on that to have any chance of drawing a conclussion...