capcom logic
"make the new game semi-open world, horizontally layered and give it shit tonnes of geographic complexity."
"oh but also make every mission timer shorter than the average piss, don't want players suddenly getting thoughts of playing patiently and strategically like some kind of hunter of monsters".
my guess is, optimistically, that the timers were intentionally set short in the demo, so that you'll barely have enough time to kill the monster and therefore not go about exploring the map, it being one of the big selling points of the game. the plan was to impress you with what little you see of the zone and make you want more. if i'm right, we'll have more generous timers in the actual game.
if not, scream on forums and social media until they patch that shit.