Yeah, there have been complaints about this.
Check preload sounds option. Not sure how it works in latest version, but sounds could be loading before the actual loader layout resulting in a long wait. Which is insane actually. Sounds should load at the same time images are loaded, after you see the custom pre loader layout.
Solution, not to preload sounds, I guess ( pre-load each sound without playing somewhere after loader layout shows up and before you actually need them )
Second thing to check is spritesheeting. For example I use sprite fonts to display loaded percentages, but if I use the same sprite font elsewhere in the game Construct will, on export, bundle this sprite font with some huge *** background images, or whatever it feels like doing, so again, a longer than necessary wait to load images not needed to see the loader layout
Solution: set max sprite sheet size to 1024 ( if it does not affect the rest of the game ) or use a different sprite font only for loader layout ( or basically make sure somehow that first loader layout images are not on the same sprite sheet with some other huge images from the rest of the game ).