I've created a tag, which i keep assigning to different tasks as and when I add them. But I noticed that when I select multiple tasks and assign them a single tag, and then group them by tags, tasks with same tag get grouped with each other (which is how it should be). However, later when I add new tasks and assign them the same tag i used earlier on older tasks, and group by tags again, the new tasks with the same tag get grouped separately.

So, now I have 2 different groups of tasks with same tags. The app should have grouped all such tasks in one group, that are using this tag.