I dont think that 11 and 8 year old children are capable of making their own decisions about things like this. I'm sure that all children go through a period of not wanting to attend church. Just like PS children go through a period of not wanting to attend school.
My DD5 loves soccer but sometimes does not want to go to soccer practice. I remember doing this as a child. There were phases I went through where I didn't want to go to church, or to softball practice, or to karate. I think it is just something that kids do.
You are kind of in a tough place because your DH will not back you up. If it were my kids, it would just be tough luck, they would still be attending. Of course they are bored, kids want action LOL. This period in time will end and hopefully they will enjoy attending church again.
I would sit your DH down and talk to him, explain how important it is to you for them to attend, and ask him to please present a united front to them on this.