What do you mean by respond? & in what situations - I.e are you talking 45 min before a correction dose starts to bring you down? Cos if you are correcting for a big high you'd be more insulin resistant so it might take longer to do anything.
Also, how are you deciding when it kicks in? Are you going off a CGM or libre? Not sure about the libre, but I know my dexcom runs at least 20 minutes behind because there is a time lag in interstitial fluid picking up the glucose levels when compared to blood.
Having said that (just to make sure I'm not assuming anything silly!) I think "impossible" is probably a bit strong. I try to wait at least 40 minutes between injecting and eating at lunch time & 20 minutes the rest of the day. I don't think that's that unusual. But the fast acting insulins are marketed as fast acting so if your doctors aren't using them themselves with a handy graph that actually shows what impact it has, they might just be over sold on the branding, it is novorapid after all!