"total annotations per task" always displays as 1

**Describe the bug**
No matter how many annotations I make in the task, the "total annotations per task" in project interface is always "1". However, when I look up the label-studio documentation ( "About Label Studio"), I found that it can be displayed as 2. I will show this in the screenshot area.

**Expected behavior**
Show exactly how many annotations have been made.

**Screenshots**
These are screenshots of my actions.

This is the screenshot I took from the document, and the circled area is what I want to understand.

**Environment (please complete the following information):**
- OS: [e.g. Windows]
- Label Studio Version [1.20.0]