After creating a new legal document template, the older legal document searches are not returning legal documents that are attached to the new template.
Custom legal document searches are built on specific legal document templates. When a new legal template is created the search does not know about the new template, and only operates on the original legal document templates specified when the search was created.
Recreate the legal document searches to include the new legal document template.
The same situation exists for assets and asset families. An asset search is built upon existing asset families. If a new asset family is created, then the asset search will need to be recreated to include the new asset family.