With the Paragraphs module for Drupal 8, you may run into trouble when attempting to reuse an existing Paragraph field in your new content or block type.

The likely scenario is that your first Paragraph field will appear as desired, but when attempting to reuse an existing Paragraph field, the widget will display an Autocomplete form rather than the Paragraph fields you require in the content type.

In fact, this is caused by a bug in Drupal 8 core.

The method to fix this (without any code), is as follows:

1. Add the Paragraphs field which you will be reusing to your new content type
2. After the field is added and saved, open the 'Manage form display' tab for the new content type
3. From the widget dropdown box for the reused Paragraph field, select the 'Paragraphs Classic' option.

There! You're all done!