Failed pharmacy billing section twice — what am I missing for the exam?

So I'm sitting here staring at my second failed attempt on the billing and insurance section of my pharmacy tech certification and honestly I'm at a loss. I've been studying for about six weeks now, maybe 2-3 hours a night, and I feel like I understand the material when I'm reading it but then the actual questions on the exam trip me up every time. My target score is a 75 to pass and I keep landing around 62-64.

The thing is, the concepts seem straightforward — adjudication, coordination of benefits, prior authorizations — but the application questions are where I fall apart. A friend recommended I work through the Pharmacy Pharmacy Billing and Insurance practice test to get a feel for how questions are actually worded. Has anyone else found that pharmacy practice tests with realistic question formats made a big difference? I feel like my study guide isn't cutting it alone.

Any exam tips from people who've already passed this section would be seriously appreciated. Especially around COB scenarios and Medicare Part D — those destroy me every time.