Best ways to moderate a brainstorming session

There comes a time in the design thinking process where I sit down with my team and we begin to brainstorm. In front of us are the problem statements we've authored based off of the user research we've performed. However, it seems that the team simply draws a blank when we're all put in a room together and asked how to address the problems our users are facing.

As a moderator, I try to ask the group questions like, "what would things look like if we change the navigation?" or "how would a non-native english speaker use this application differently?" There is a small bit of chatter and then one or two people say something to the effect of "can't you just tell us the answer?"

I'd like to know the tricks other UXers have used during this step in the design process to engage members of the team to think creatively and truly participate in the process. Yes, I can make all these decisions, but that's no fun! I want to hear what people think, but I fear that I'm not providing an environment where they're comfortable enough to share their thoughts.