Apex Legends high Input lag tied with fps

@EA_Atic Yes, I discovered that my gpu usage is 99% when the input lag starts to kick in. Everything else seems normal.

@EA_Atic  I've found a place that can quite perfectly recreate this bug. It's on Olympus, next to turbine there's an elevated house with a waterfall behind it, there's also three loot boxes with one of them spawning gold loot. If you are close to the loot boxes and facing the waterfall, you'll instantly feel the input lag. Tested with several friends' systems, and it is apparently universal, just not nearly as severe as mine.

I'll link a picture to help aid my terrible explanation

so I've been having this since the start of season 9, or maybe since the split. I can't remember but this has been going for ages. 

I realised it only affects the mouse as input, not controller. I can play fine for hours with the controller and there is 0 input lag. It actually feels a lot better than playing on the Xbox for me since I can play at 120+fps while Xbox caps framerate at 60. While using the mouse, on the other hand, I can feel a delay at many random times during a match, sometimes a very strong delay. The waterfall is the most obvious place it happens, I have to actually avoid fights in that area as the frame drops dramatically there and the input lag is horrible. What is interesting is that even though the frame drops in locations such as the waterfall, it is not actually low enough to supposedly impact the game, I'm talking 80-90 fps, instead of the usual 120-150fps. It's no reason to make my game so sluggish and increase input delay. Also, there is 0 input lag on the controller even at the waterfall. I can play perfectly fine. 

Adding to the above, I thought it could be related to using a wireless mouse, and maybe the high use of GPU or CPU was impacting the wireless dongle functionality, but I tried a wired mouse and also a wireless controller using the same USB port. Same results: 0 delay with controller, but delay with mouse. 

So this all could just be a placebo effect as I don't have any real time data to back it up but I mightve found a solution.  I was messing around with the steam controller config and I decided to bind my controller to mnk binds to feel how mouse like aiming felt on a joystick. In the middle of a game I switched back to mnk while leaving the controller plugged in and I immediately noticed my mouse felt different. It felt way better and much more like how I'm use to it feeling so I unplugged the controller to find out my mouse felt insanely sluggish again. I than closed my game out and went to steam launch options and added -nojoy. Loaded up firing range and sure enough my mouse felt responsive again. Give it a try and see if it works for you. Unfortunately controller is disabled while doing this though.