I take it you do want them to breed.
Though I am no expert on breeding bearded dragons, it doesn't always happen instantly. It could take a few weeks or more till the females are ready to be bred by the male. If he has never bred before it may take him awhile to do it right. It is also possible your females just don't like him.
Only real thing you can do is make sure your females are healthy, at least 300g in weight (more is better) and have clean bills of health. Checking fecals of all females and the male would be a good thing as well, to make sure they don't have anything that could hamper their ability to reproduce.
I hope you are fully prepared for the responsibility of breeding your females. It takes alot out of them and out of your pocket book.