For my non-coding problems, I just create it from scratch depending on the position/needs & spend a bit of time navigating the scenario myself and store the question in my notes.
As to failing a question, failing a single question isn't necessarily a deal breaker in itself - it's showing a pattern of not meeting the bar that is. I may rate someone a 2 out of 4 if they didn't go into sufficient depth in a particular question I asked, but I probably won't stay in the way of hiring them if they did ok otherwise and that failure was just an aberration. Loss of integrity is perception that is likely to sour people on any upside of hiring though, and overcoming that bar is incredibly difficult - if someone is clearly rehearsed on a particular question and is dishonest about it, they're probably not getting a 3 or 4.
How the process for us works is if you are a strong enough candidate, we have no qualms giving multiple offers simultaneously and working out the reqs afterwards, even borrowing against a future one if we have to. How we evaluate is probably also a lot different & more thoughtful than a lot of candidates realize - we're discussing leadership traits, strengths & weaknesses, and skills in our debriefs and what we all observed about the candidate in our sessions. No candidate does perfect in any given session - even candidates who I have given 4s for have slipped up or had negatives observed.
I’m usually not even asking a coding question in my session - I set up a practical/common problem beforehand and we explore the scenario together. I can assure you that many candidates don’t pass my session necessarily, even if they have proven in other sessions to be brilliant coders - I’m not looking for technical brilliance in most of the interviews I give, and neither are the hiring managers I work with. To me, focusing on the coding is most important on the technical screen, not the full panel - once you reach the full panel, your goal is to demonstrate technical leadership, which includes expertise in knowledge, coding competency, focus on UX, and some other areas for more senior roles (conflict management, responsibility, navigating different stakeholders for product/project decisions, etc.).
If all your focus is in is just the coding questions, you’ve likely already set yourself up for failure.