Things that don’t follow the way I understand physics and technology to work. I enjoy sci-fi stuff a bit but when it doesn’t ’work’ I have trouble suspending disbelief and enjoying. Time travel is an easy example, I find most media with time travel to be exceptionally frustrating and taxing. Pending space, worm holes, silent floating and fast aircraft’s. An antidote just immediately saving the world without any protection or logistic considerations, just magical gets into everyone’s systems so the world is saved. It can make brainstorming really difficult for me. I’m not sure if those examples help or not, it’s what immediately came to mind, I’m sure there’s better.