Troubleshooting journal and journal_input fields
If journal fields are included in the form as well as in the activity formatter, it will create a separate stream based on the Journal field type.
The journal fields are of three types: Journal, Journal Input and Journal List. If the custom field is created with type Journal and if the activity stream has included this field, then the text entered will show up in both the activity stream and another new set of stream. However, if the custom field is created with type Journal Input and the activity stream has included this field (only), then the text entered will show up only inside the activity stream and nowhere else.
Also, if the field is created with type Journal List with a dependent field as either of the other two fields, it will generate a separate stream with limited functionality (similar to the activity one).
In your browser, access your instance and navigate to a record form (for example, an incident or change record).
Create two fields on the form using sys_dictionary: Comments (of type Journal) and Notes (of type journal_input).
Create a test record inputting some value for both the fields and make sure both the fields are added to the activity formatter.
Save the form and note the update on the activity stream.
The text entered for Comments will show up in both activity stream as well as on another new set of stream.
The text entered for Notes will show up only inside the activity stream and nowhere else.
Note: Avoid using field type Journal to avoid duplication of the comments.