do not receive trello notification

[Tran_Le_Thuc_Vy]

We have created a board for group. Until yesterday everything is ok, but today no member receive notification when we change information in the board (include email, desktop, app).

We can only see the activities of the members when we click the "activity" in the menu bar

We have enabled the notification function.

[Torben_trello]

Would you mind reaching out with an example (screenshot of the card you expected a notification for and the link to the board) via trello.com/contact so we can check it out in detail?