That's just the wildcard nature of our yeasty friends.
There is nothing "typical" in brewing...every fermentation is different, and should not be used to compare one with another...you can't do that.
No two fermentations are ever exactly the same.
When we are dealing with living creatures, there is a wild card factor in play..Just like with other animals, including humans...No two behave the same.
You can split a batch in half put them in 2 identical carboys, and pitch equal amounts of yeast from the same starter...and have them act completely differently...for some reason on a subatomic level...think about it...yeasties are small...1 degree difference in temp to us, could be a 50 degree difference to them...one fermenter can be a couple degrees warmer because it's closer to a vent all the way across the room and the yeasties take off...
Someone, Grinder I think posted a pic once of 2 carboys touching each other, and one one of the carboys the krausen had formed only on the side that touched the other carboy...probably reacting to the heat of the first fermentation....but it was like symbiotic or something...
With living micro-organisms there is always a wildcard factor in play...and yet the yeast rarely lets us down. So it is best just to rdwhahb and trust that they know to what they are doing. It sounds like you are brewing by a calendar, or instructions and not by what your beer is really doing, the problem is that yeast don't know how to read so they seldom follow their scripts. They dance to their own tune and its seldom 4 x 4 Time.
Don't assume the worst with the yeast, realize that they've been making beer since long before our great great great grandfather copped his first buzz from a 40 of mickey's out back of the highschool, so they are the experts.
Yeasts are like teenagers, swmbos, and humans in general, they have their own individual way of doing things.
And worrying because it's not happening how fast or slow you think it should be is really not worth the energy.
It may not be what you expected
it to be but that doesn't mean anything's wrong.
And remember, as the sticky says, fermentation can take 24 to 72 hours.
And that doesn't mean airlock bubbling...that means numbers on a hydrometer....