I see a number of posts where people have failed an ISC2 exam or have run out of time on the exam.
So far, I have taken two ISC2 exams and have been successful passing them both in well under the allotted time given. For both exams, I have used the official ISC2 materials.
The exams are a bit different than other Certification exams (Novell, a plethora of Microsoft, Cisco, etc.) that I have taken through the years. Since they are different, I strongly urge anyone that is pursuing an ISC2 Cert, to pause, step back and pursue the ISC2 CC Certification first! This will give you an idea of the ISC Tests and process work at no cost with the exception of a small Annual Membership Fee after passing the exam.
Here is a the link to the free CC training information: https://www.isc2.org/landing/1mcc
Thor Pederson has a excellent course on how to study: https://cart.thorteaches.com/cissp-how-to-study/
Don't let the CISSP in the course name deter you from taking his free course. It has a plethora of information on how to study, create a study plan and general guidance to help you be successful in your certification pursuits.
Last but not least, Certification tests from ANY vendor are designed to be an in depth test of your skills and knowledge. If they were easy, then anyone could pass the test and by passing the test, we would simply become another of the "herd." Our goal in Certification should be to have validation of our skill sets so that we stand out from the "herd"!
Hopefully, my post will help! Good Luck!