Using GetMessages with the "AfterId" parameter of MessageCollectionOptions... how does this work?

[OracleCura]

Help me out here, I'm trying to figure this out.

I have an instance of the AssistantClient class, and I call GetMessages. If I pass in the thread Id, I get all the messages. Great.

What if I already have all of the messages except the latest one? Well I can pass an instance of MessageCollectionOptions in there too, and AfterId seems like it might be there for this scenario, but... it doesn't seem to work the way I expect. If I provide the Id of the latest message I've received, or even the Id of the latest message I've sent, I always get the same thing: All of the messages... except the latest response from the assistant. I don't get it.

Basically if I want to reliably get the latest response from the assistant, I have to fetch all of the messages? That can't be right, can it?

How is this supposed to work? Does this not work as I'm expecting it to, at all? I can't find any documentation to explain this anywhere. If there is such documentation, please let me know where I can find it.