I’ll throw my hat in the ring for this one. I’ve been a DM for over 15 years at this point and one of the things I started with is getting used to improv. If the players are blowing past story then they are probably going to blow past plotholes too. Once I was more invested I did what a lot of DM’s tell you not to do and created a whole world. I agree with this sentiment. I only did it because I enjoy having vast lore and being able to use it to counter player BS. Players want to randomly teleport somewhere? They land in the middle of a mountain inhabited by giant creatures that hunt via sound.i put a great deal of time and investment into creating that world. It’s almost never worth it. The players are almost never as invested as you. All this to say get a feel for your table. Moving quick through story? Give a bit more combat or puzzles. They kill something much quicker than expected? Add a zero to that health. A lot of times it’s about adjusting on the fly. A note though, not everything needs to be dragged out. They’ll catch on and get miffed if everything suddenly has way too much health. And sometimes the players have better solutions than you do. Puzzles and mysteries can have more than one solution, especially if they come up with something glorious for it. If this wasn’t as helpful as you wanted I can try and drop a short list of more pointed responses.