Once you wrap your head around VLANs, it all makes sense. But there is a learning curve, for sure.
If you want help with it, a new thread would be the best way to go, and we can start by looking at your main router and then move onto the AP.
If your problem is solved, please consider marking this topic as [Solved]. See How to mark a topic as [Solved] for a short how-to.
Thanks! 