[Koha] Regarding Notices in 3.8

[rocky bang]

Hi koha,

I am using koha 3.8. and started notices section in koha.
The problem i am facing is when i edit the checkout noitce some of the
fields are not reflecting in the output mail such as <<issues.date_due>>
<<issues.returndate>>
but the fields such as <<biblio.title>> <<biblio.author>> is reflecting in
the output mail.

*The sample output mail for checkout is as below:*

The following items have been checked out:

Flora Of British India    by      Hooner, J B,
Due Date:

Any suggesstions regarding this problem.

Thanks in advance.