This is normal. Allow me to explain...
When you see an enemy in game, you are seeing where the person was a fraction of time ago. It takes time for information from another player to be sent to the server and back to you.
Let's say it takes you a 0.25 seconds to receive the information set from another player. In 0.25 seconds, the enemy could be a full step further than what you are seeing. The lag comp implemented is meant to try and reduce this effect, but it is by no means perfect.
This effect is amplified with the speed you are moving. Let's once again say it takes 0.25 seconds to receive information. If you are in close combat and a player walks leisurely around a corner, they will see you probably for only 1/10th of a second more, not that much. However, if they run around the corner with speed perks, they may have time to see you and get shots off before they even appear on your screen as the information may not have reached you yet.
There's not much you can do to mitigate this. My advice is to try your best to make sure you give yourself the advantage. If you're the guy ripping around the corner, you'll win more often than not. As for the sniper issues, it's a little trickier. It's a precision weapon, and hotbox detection has been, and probably always will be, a touch off. Just do your best!
I hope this helps.
Do you think this is being hindered by the fact that I am running my PS4 wireless? What it seems to me is this..... say we are both running around the corner with speed perks. All things being equal more times than not it seems they can pull up their weapon, shoot and kill me, before my weapon is even up. Like I said, sometimes it is so prominent that I am disgusted enough to just log off. Other times it seems more even, but hardly ever do I feel like I have had the advantage in any way. I am just trying to figure out if I suck that bad or if it could be a connectivity problem. lol I would be happy with just a level playing field.
There could be a few things at play...
1. Are they running the "Ready Up" or "Quickdraw" perks? That could give them an advantage in the way you described.
2. Are they the host? The host will always receive information first, and is always at a slight advantage.
3. It's possible they are a COD veteran. I know there are many players who have totaled over 100 days (myself included) combined across COD titles throughout the years. That's a lot of practice.
I don't think running wireless would cause you to have a substantial problem.
I tend to always aim a little in front of the enemy if on the move, with a sniper rifle (it's a good & consistent strategy), the gold knife is unlocked at 5th prestige bonus, giving the ability to recover quicker, some say - it may enhance the lunged attack...(players are using this gold knife alot more) it's probably why you are getting knifed easier.
Dumble- I might suggest you try running an ethernet cable to your modem/router to see the difference a "wired" connection makes. The data transfer is cleaner in my opinion and does make a difference in game play. It does give a slight edge to wireless and sometimes that is all you need. All your download content will be faster and it overall, just speeds stuff up (in my opinion) You can do a search in the forum threads for wired vs wireless connectivity to see the general consensus- best of luck and have fun!