Eventual consistency / Lost Updates at play? I have tried sweeping the "Low Priority" emails; whenever I clicked the tick that group entry was gone. So far so g

Eventual consistency / Lost Updates at play? I have tried sweeping the "Low Priority" emails; whenever I clicked the tick that group entry was gone. So far so good. However, whenever a new email popped up and was classified in that group, the whole group appeared again. Or am I just misunderstanding the feature and do I just have to mark individual email as done one by one?