Create Board API returns wrong items and item count

Create a new board from a template by this API , will return 1 or 0 item and wrong item_count. Then read the board immediately by this API, will get all items and correct item_count. Create board API endpoint is supposed to return all items as Read Board API. This is example:

Then I query the board immediately:

Expect result:
Create Board should return same Items and Item_count as Read Board. I think this is a bug of Create Board API.