I'm having Issues with surfaces

[Nux]

[This uses GMS2's new camera system]

Pictured above is my problem; when zooming closely into the application (low resolution games), sprites appear to shake uncontrollably when I move with a smooth camera.

Spoiler: OLD

Extra: The background sprite is on an asset layer.

I really want to know how I can fix this; it's driving me insane.

Spoiler: Code Dump

this is all just rough work; i want to get somewhere where this works before fixing memory leaks and code.

Spoiler: Room Start

/// enable views
view_enabled = true;
view_set_visible(0,true); // main view

/// create the camera
gameCam = camera_create();
camera_set_begin_script(gameCam, camera_update); // assign update script to camera
view_set_camera(0,gameCam); // assign camera to view 0

Spoiler: Draw End

// note: this is where the circle is drawn, it's drawn onto a seperate
// surface, but that isn't the problem, since it does the same when drawing to application surface

surface_set_target(global.sPixelated);
draw_circle(10,10,10,0);
surface_reset_target();

/// pixelated
if surface_exists(global.sPixelated)
    draw_surface(global.sPixelated,global.xView,global.yView);
else
    global.sPixelated =
surface_create(surface_get_width(application_surface),surface_get_height(application_surface));

Spoiler: Post-Draw

draw_surface_stretched(application_surface,0,0,windowWidth,windowHeight); // these two variables are the width and height of the user window

Spoiler: camera_update Script

/// update camera to follow a view

// get xy
global.xView = lerp(global.xView,mouse_x,0.1)
global.yView = lerp(global.yView,mouse_y,0.1)

var projmat = matrix_build_projection_ortho(IDEAL_WIDTH*0.1, IDEAL_HEIGHT*0.1, -32000.0, 32000.0);
camera_set_proj_mat(view_camera[0], projmat);

var cameraMatrix_lookAt = matrix_build_lookat(global.xView,global.yView,-1,global.xView,global.yView,0, 0,1,0);
camera_set_view_mat(view_camera[0],cameraMatrix_lookAt);

EDIT: I'd like to add, drawing things correctly does work in the draw event. However, everything else starts to vibrate:

(seen by the round circle being static, but the character spazzing as well as the pixelated circle.)


EDIT#2: I got a patchwork solution, but it requires drawing in the draw-end event, and also drawing on the surface after it has been drawn. Which confuses me a lot.

if surface_exists(global.sPixelated)
{
    draw_surface(global.sPixelated,global.xView,global.yView);
    surface_set_target(global.sPixelated);
    draw_circle(10,10,10,0);
    surface_reset_target();
}

And anything else needs to be drawn before the surface has been drawn or it makes that vibrate. I have no idea; I'm clearly doing everything wrong.

EDIT#3: Does anyone have any ideas as to why this is happening? Please.

I've found out that by even accessing a surface constantly is causing the problem; changing this:

to this:

Causes This to happen:

Whereas the commented code does this:

Which is the desired effect.
I have no idea why accessing/resetting the surface target would do this.

 

[Nux]

Bumping because I feel this is some kind of bug; I'm not even drawing to the surface, only setting it as a target. So that's strange.
Are there any surface gurus who can first laugh at me and then tell me what's up
Thanks!

P.s. I won't bump the thread any longer if nobody has an explanation.