I'm a CISSP too, nothing I read in the ISC2 study guide prepared me for the test. I have 25 years in IT and 5 years building Cloud Security and transport. The book I read did not prepare me at all for the test and its ISC2 Official Study guide.
In order to pass this you have to learn to take a test with trick question. This is a total waist of time and now I must be done again and they will get more $$.