11 year old step son struggling with faith

For context I have 3 children of my own and my wife has 2 children. We are both from divorced families. While my ex and I remained in the church and coparent well with the fact our children will continue in the church, my wife’s ex did not. He had a mid life crisis and left the church at the start of covid. He is now actively against the church and does not want his children attending but luckily had it in the decree that she has a right to take them to church every Sunday. She got this in luckily when he stopped attending church but wasn’t anti-LDS yet.

But now he has been constantly talking bad about the church to his son and persuaded him to no longer go to church on his time and only on our time with them (50/50). We agreed to let this happen because we wanted to give him his agency because we could see this back firing forcing him to come especially with her ex involved knowing he was going against his will. He is a very smart kid and very analytical. He is the smartest in his school. He is at the point where he is questioning everything and doesn’t like it when you get to answers where you need faith. Today he wouldn’t get out of bed to go to church and was crying saying he no longer has faith in god anymore. This isn’t like he simply doesn’t want to go and wants to stay home and play games and stuff, he legitimately is having a faith crisis and wants to believe in god but doesn’t know how.

We are doing everything we can, reading scriptures, holding biweekly FHEs, going to activity days (we are actually the leaders for this). Taking on this new role as step dad has been very complicated. I have been very careful to never punish him and leave that to his mom. I will remind him of things his mom asks him from time to time. I’ve just tried to be there for him be his friend and gain his trust. We have been married for almost a year now. I’ve read lots of books on step parenting. My wife has asked me if I could really try to focus on being a good priesthood example to prepare him for getting it at the end of the year. But now I don’t even know if that is a possibility.

Does anyone have any advice for situations like this? It is very difficult with her ex taking advantage of his fragile testimony. It is very difficult knowing how to talk to him without going against his actual father who he will always trust more than myself. How do I show him a good example of the priesthood? Thank you everyone for any advice.