You're running into 1-5% rendering lag, which is a result of overloading your GPU >80-90%. The encoding lag reported percentage appears to be a byproduct of this, as it is following rendering lag exactly.
You've got game mode disabled, which is good... but you'll also need to limit your GPU usage, otherwise OBS just doesn't get enough resources to composite the scene. I'm not familiar with apex legends, but I've heard this game doesn't really have a way to cap fps without vsync (which if you're using a 144hz monitor, that won't do anything to help unless you're constantly at 144fps+). Something you could try is downloading "Nvidia Profile Inspector" (separate program, not the normal device settings menu), and manually set an FPS cap for your game (select the game in the top drop-down, and I believe it's "Frame Limiter v2" that should be set to your desired FPS).
Something else to try is to turn off Psycho Visual Tuning, and drop the quality setting down from High Quality. This may free up some resources, but this is more of a long-shot.
Side note, it looks like you're using CQP:20 for your encoder. Don't do this -- set it to CBR, and set to 6000kbps or lower for twitch (it looks like the "Enforce Streaming Service Encoder Settings" is saving you by capping it at 6000kbs).
