Character styles cannot override pure paragraph properties like "fully justified". They can only handle formatting on character level. And justification is not one of the properties of a character.
What could theoretically go wrong then?
1. You did not select the text of all subsequent paragraphs when applying the style.
2. Subsequent paragraphs are not subsequent paragraphs, but individual lines of the same paragraph ending with a right indent tab followed by a forced line break and not with a paragraph sign.
Check "Show hidden characters" and inspect the paragraph(s) if issue 2 applies.
3. You selected several paragraphs, right-clicked the new paragraph style in the Paragraph Style panel and applied it with choosing: "Apply "[Name of your Style]" Then Next Style". Where the "Next Style" defined in your paragraph style has a different format than "fully justified".
I created a paragraph style that is supposed to fully justify. It worked on the first paragraph, but subsequent paragraphs are only applying the first line indent and not the full justification.
Are the subsequent paragraphs using the same style? In that case:
- put your cursor in the correctly-formatted first paragraph
- open the Paragraph styles panel
- right click the highlighted style name in the panel, and
- choose Redefine Style.
This will ensure that all paragraphs using that style have the same definition.