What is the way to deal with a husband who believes that the mixing of women and men who are not mahram is permissible, watches films that contain bad things, and rejects advice, despite being a good person?

Continue to advise your husband and his relatives in the best way to help change what is wrong (munkar), and be keen to avoid participating with them in transgressions, especially bad movies. Control your emotions of sadness, jealousy, and anger by avoiding despair and alienating the one being invited to guidance. Remember that your husband is a Muslim, prays, and is kind, so be patient with him and continue to invite him to the right path.