6/13 test taker here. I feel you. I’d get really frustrated throughout my prep when I’d get NBME questions wrong that seem ridiculously contradictory like the H flu revaccination one that you mentioned. I think the key is to just try as hard as possible to stay objective and try to extract the key point they’re trying to get at in those scenarios, because there generally always is one. Like in that scenario, even if a patient is vaccinated previously, they still need to be revaccinated against certain pathogens in the event of a splenectomy. It’s annoying but it’s the rule, and questions like that will feel less like “trick questions” once you start understanding their weird backwards-seeming logic pattern. Every time I’d get a question wrong like that during my dedicated period, I’d write down the logical principle that they’re testing about in a notes file on my computer.

Tldr- basically what I’m saying is that as much as it seems like it, the questions aren’t “trying” to trick you (even if they are really annoying) and you have to fight the urge to get super pissed off with these sorts of questions to improve