Because it’s not working against druids or rogues.
Depends, the paladin must have a seal active to land this Judgement and also it can be dispelled or removed in many ways. The not full list here:
Edit: If you were wondering about your second question, whether if it doesn’t apply to druids or rogues, it doesn’t have any different effect. It could have been dispelled or removed as I said initially however.
If it doesn’t work at all, e.g. player isn’t slowed and it wasn’t dispelled or removed consider submitting a bug report.
That wasn’t the question, but thanks.