If you are not able to see a template you were able to see before, it could be because of the Contract Type or Procurement Category. If you are a Template Creator, confirm the Contract Type and add the Procurement Category values. (The "Procurement Category" is just copy of the parent agreement).
Or, it could be permission-based if you are accessing a new project and the Contract Template is not there for you to select. A visibility condition for the template appears in the properties portal on the Overview tab.
Remove the visibility condition using the following steps:
Please note that you must have the Template Creator permission on your user account to edit, create and copy templates. Reach out to the Template Creator/Template Owner if you are unable to edit the Contract Type, Procurement Category, or any visibility conditions.
I hope this is helpful,