For whatever the reason things just don't click. Part of that could just be how the information is being presented. Also, you could just need a reboot, specific to a given topic.
So if you're just not understanding the CPA Review material for that topic try something else.
I know for passthrough and corporate bases, I needed to start over. So I took a day to pour through my old textbook on the subject. Whatever gaps I still had, I searched the web for. Then I wrote out about 2 pages of notes. I reviewed that and took like 10 MCQs on that alone, with those notes in front of me. And it clicked.
Then, I didn't need to have the notes in front of me.
In short, maybe you need to just take A step back before you can move forward. I know you spent a lot of money and time on review materials. But it's like buying an expensive power saw. It's just one of many tools available to you. Some jobs need different tools.
Good luck.