As a standard, the saved search will not display all the content of the long text field.
Solution:
Change the field type for the existing field from Long Text to Text Area.
Please note that changing the field type may cause in the removal of existing content.
Take a backup of the field details if possible.
OR
Create a new custom field
Use the field type as Text Area
Add the content manually from the existing field(Take the backup of the field details if possible.)
Add the formula text field instead of adding the field directly in the saved search