He has mental health problems
Dad is a title that carries a lot of responsibility. Therefore, if a father is abusive or careless with how he handles his family, the likelihood of having children with mental health problems increases.
If your man wasn't treated right by his dad growing up and he has mental health problems like depression, they might be connected. This can happen when he hasn't gotten therapy to help him face that childhood trauma.
He struggles with his masculinity
Masculinity is at the core of most men. Strong masculinity won't struggle to lead, make decisions and handle other things that comes naturally to men.
If he is often insecure about his masculinity or doesn't know how to be a man, it might be because he didn't have a healthy relationship with his father.
His dad didn't set a proper foundation for him to secure his self-confidence as a man.
He is clingy
Clinginess often disguises itself as genuine love but it is not. It is a sign of someone who is afraid of being abandoned, which is also connected to daddy issues.
This trait shows that he has trust issues, which stem from a father who deprived him of the attention and love he needed. It's not normal that he gets anxious when you're away from him or that he's possessive over you.
If this is your man, encourage him to get the help he needs for proper healing to take place.