"A mistake repeated more than once is a decision" Paulo Coelho
These are usually common:
Not being sure if the relationship will lead to marriage:
Commitment issues leading to situationships
Lack of ambition
Relationship coaching and mentorship will help you have a better relationship or help you make great decisions, work on yourself whilst waiting for the one, resulting with a much happier and healthier self.
You have the call to work on your relationship or walk away if its neccessary.