I check on my mail file and openntf was the person who signed de follow up view ($Follow up) with the same date as the template.
I check in the template and it work, the mail mark with follow up apears in the follow up view. But no refresh or no replace would change anything on the mail database.
I then decided to remove the follow up view from the mail file and did a new replace design with the open ntf template, now the foloow up view show the foloow up item.
Thanks for your time, maybe something was wrong on my mail database.