Unfortunately, most people have left a job because of a negative experience at that place of employment. No matter what happened, leave it there and move on.
When interviewing for a new position, never speak negatively about your former employer. No one likes a complainer or whiner. Rather than speak about the negative, try to talk about what you learned or the positive growth you had while employed there.
Always remember the rule, “If you don’t have something nice to say, than don’t say anything”.