Manners dream meaning is explained below using 4 different sources. Each interpretation is shown with its source.

Interpretation 1 — Stearn Robinson - Tom Corbett

To dream of bad manners, whether your own or those of others, suggests that you are standing in the way of your own progress due to an inferiority complex which you should try to overcome; but a dream featuring overprecise manners indicates that you are contemplating some social climbing which will not work out well—give it up.
Source: The Complete Guide to Interpreting Your Dreams Author: Stearn Robinson - Tom Corbett

Interpretation 2 — Gustavus Hindman Miller

To dream of seeing ugly-mannered persons, denotes failure to carry out undertakings through the disagreeableness of a person connected with the affair.

If you meet people with affable manners, you will be pleasantly surprised by affairs of moment with you taking a favorable turn.

Source: Ten Thousand Dream Interpretation Author: Gustavus Hindman Miller

Interpretation 3 — Joan Seaman - Tom Philbin

1. If a person is well-mannered, it is a hint that he/she will be easier to deal with.

2. If a person is poorly mannered, they will be difficult to deal with.

Source: New American Dream Dictionary Author: Joan Seaman - Tom Philbin

Interpretation 4 — Dream Explanations - Anonymous

Dreams of manners represent constraint, respect, and that you are grappling with your authentic expression versus what is socially or politically correct.
Source: Strangest Dream Explanations Author: Dream Explanations - Anonymous