I am guessing you have it blowing air out of the case which means as the case temps ramp up while gaming it is pushing warmer air through the rad. This explains higher temps at lower utilization than when stress testing which only effects the CPU and VRMs. 

What case are you using and what is your fan setup in there?

Right off the bat though I am seeing a whole lot of extractor fans and not a whole lot of intake. This isn't ideal, while yes you will be pumping out the warm air from the case faster you are also sucking air in through every gap, hole and grill in your case due to the negative pressure inside. Negative pressure is popular with some builders but it has to be within reason. Too much and you run into the situation where you are just spinning fans with not a lot of air getting through them. Even water cooling used air to cool the coolant, air cooling requires air, too much of a vacuum inside your case and you end up with less air going though your radiator. 

I am not going to get any more technical here, this is a highly subjective topic and in many cases the orientation of the radiator fans makes very little difference. In my experience though, this is how I like to set things up:

Radiator as exhaust (pulling air from inside the case and blowing it out of the case):

All front fans as intake, rear fan as exhaust and radiator mounted on the top of the case also as exhaust.

Radiator as intake (pulling air from ouside the case and dumping it inside):

Radiator mounted on the front of the case as intake with at least 1 other fan doing the same, top fans as exhaust, rear fan as exhaust.

Both these setups should perform more or less the same. With the rad intake config your GPU and VRMs may run a little hotter and with the Rad as exhaust your CPU may run a little hotter but in both situations we are talking minimal figures.

What you have now is not properly balanced, it sounds like someone went on to an enthusiast forum and read "negative pressure is best for cooling" and went the whole way with all fans as exhaust. That isn't what negative pressure being best means, it means leaning toward not all out. Fans should always be set up more or less balanced with one maybe 2 (with loads of fans) fans tilting the case pressure to positive or negative. I personally prefer positive pressure, it means less dust buildup in the case.

I gave my two favorite configs in my last post. At the very least I would open up your case and flip the front fans so they pull air into the case 

Rather than vsync I would look at your games settings, if you can bump up the quality settings all the way and maybe turn on SSAA you should be able to disable vsync, have everything look amazing and not be hitting super high FPS.

There is one last thing to check on your current cooler:

Open your case and look for the cable that comes off the CPU block, it should connect to one of your board's fan headers. You shouldn't need to disconnect anything, just trace the wire coming out of the block. Make a note of the header label then go into your UEFI and make sure that header is set to "Water Pump" -> "DC" -> "Full Speed".

If it wasn't before you can check your temps again after doing this. 

So in your situation, you are playing BF1 and temps are in the mid 60s and all is right with the world, suddenly windows decides to run an update in the background and your CPU usage goes from 80% load to 99% load, the fans ramp up but by the time they have you have spiked to 76c, it was only for a moment but that is what you see on your monitoring app.

Far more important is your average temps, if those are close to the max temps and your max temps are in the high 70s - 80s then your cooler is inadequate. So:

Max temp: 90c

Avg temp: 55c

This is all good, there is no way the CPU was running anywhere close to 90c for any long period or the average couldn't possibly be 55c.

Max temp: 80c

Avg temp: 75c

Get a new cooler. While even these temps are not fatal to your system they will shorten it's lifespan.

You have to bare in mind that average temps are exactly that, the averaged temp including highs and lows. So to get an accurate reading, open your game, tab out then open your monitoring app, tab back in to the game. Once you are done playing, before quitting the game, tab out and look at your temps. If you start the monitoring app too long before you start playing the idle temps will be taken into account with your average and make your readings seem lower.

Check the settings in your UEFI for your pump as I said earlier. Once we know where you are at there we can delve into improving your temps or determine if your cooler is or isn't up to the task.

Ultimately though, even set to the "silent" profile the pump will ramp up and temps will go back down. I did find out that it is better for the pump to run at full speed all the time, it should last longer without the speedups and slowdowns given coolant flow and inertia and a bunch of other sciencey reasons 

The reason we all mentioned those temps being on the high side is that you are running at stock, not overclocked. Wardog, Parsec and myself all run AiOs in our systems ranging from H100i to H110i, all 240 and 280mm radiator versions. Your temps are significantly higher than ours but your radiator is a 120mm, half or less than half the size.

So, check to make sure your pump is set to full speed in the UEFI

Make sure you have a balance of intake and exhaust fans, buy another one if you have to they are cheap.

Set your fan profile for your AiO fans to a more aggressive profile or max it out (if noise isn't a problem for you)

Then enjoy your system. Don't be afraid to dig into things, do some research, ask questions here. You are embarking on a journey where there are so many paths to take. Half the fun in owning a beastly PC is tweaking it and trying to get the most out of it.

The one thing that I can see that is diminishing your AiO cooling performance is not the orientation of the fans but rather the fans themselves. They are the correct type (high static pressure) but they are aftermarket and tuned for silent operation. This means that even at full speed they are not pushing enough air. 

You could pick up something like these:

https://www.newegg.com/Product/Product.aspx?Item=N82E16835181027&cm_re=SP120-_-35-181-027-_-Product       (copy paste link)

Corsair's High Static Pressure fans always have an "SP" prefix then the fan size. The ones I linked are beastly and will make a lot of noise but they also push almost double the air of your current Enermax Twister Pressure fans.

Your temps are not great with the current setup but they are not terrible either. Whoever built the system for you was clearly going for a silence>performance setup. This isn't a bad thing, a lot of people prefer silence to cooling performance (so long as everything is within tolerance). If you want to tinker and improve things as well as possibly overclock in the future then I would pick up the fans I linked and have them installed for you. It would probably be best to have the person who built the setup do it for you, they know the build and if you have a warranty it saves you headaches later on. You could also ask them if they have the stock fans for the AiO, the ones on there did no come with the AiO cooler, it could save you some pennies if they can just slap the originals back on there for you.

I personally like it when my stock H105 fans ramp up, sounds like something beastly is happening inside my case, a little like the roar of an exhaust on a v8, makes me smile every time 

Let us know how the temps are after you have made the tweaks I suggested.