Thanks!
It looks like first country connected to channel is set on the cart but looking at the cart object it looks like that there is no country on cart but there is on cart.OrderCarrier. In accelerator checkout for delivery methods and perhapps in other places the same is done all over againg without checking the cart country.
But i would conclude this as the accelerator has no support for multiple countries on one channel but is possible to fix in the project.
_requestModelAccessor.RequestModel.Cart.OrderCarrier.CountryID
Controller base
cart.SetChannel(
channel,
channel.CountryLinks.FirstOrDefault()?.CountrySystemId.MapTo(),
SecurityToken.CurrentSecurityToken);
DeliveryMethodViewModelBuilder
var ids = _requestModelAccessor.RequestModel.ChannelModel?.Channel?.CountryLinks?.FirstOrDefault()?.DeliveryMethodSystemIds ?? Enumerable.Empty();