Is he telling the truth

I'm not looking for anyone to tell me to leave my boyfriend or anything. Just if they think there is truth in what he's saying about his oldest daughter. He has 7 kids by two different women. 1 is by one woman and 6 are by his ex wife. 5 live with him full time. 1 lives with his mom full time and he gets him on breaks but his oldest daughter lives with his mom and doesn't talk to him. Every time I asked why he said he doesn't want to talk about it and it will just make him cry. He finally told me why they don't talk. He claims his mom was very abusive when he was younger and always wanted to take his oldest daughter. When he was going through psychosis his mom convinced him to sign away guardianship to her and said that he could still see her and his mom just ended up alienating him from his daughter and told her so much stuff that she hates him now and it's why they don't talk. I'm wondering the possibility of this happening. If he was going through psychosis why would he be allowed to sign a legal document signing her to his mom? Also curious, are you allowed to have custody of your kids if you have psychosis? He is on medication so I suppose that could be real but can you have custody of your kids going through that? I'm not trying to accuse him of lying but I just don't understand how he could be allowed to sign anything when he wasn't mentally well

@G.G i myself have a lot of baggage. I typically can't trust my gut becoming of childhood trauma I just assume everyone is lying to me. I know that's not healthy which is why I reach out for opinions now. Many people in the past have said I have too much baggage so I try not to do that to other people.

@Mommaof4 he signed over guardianship to his mom. Not his rights. He pays child support for both kids that do not live with him and receives child support for the 5 in his custody. From what I understand she's a teenager so it's harder to force a teenager to see you than it is a small child and she doesn't want to see him because of things his mother has told her.