How do you stop a MATLAB GUI from clearing axes between plot commands?

I have a GUI that I'm using to place initial locations for a 6DOF sim. I want the points to use different markers (a red circle and a gray triangle), but every time I use two plot3 commands, the GUI plots the first then clears and plots the second. I'm using the hold on ... hold off command. Is there a way to fix this or use one command?

Here's what happens after the 'Place' button is pressed:

Code for reference:

hold on
plot3(app.UIAxes,missile_init_x,missile_init_y,...
    missile_init_alt,'ko','MarkerSize',15,'MarkerFaceColor',...
    'r') % <--------- Some form of clear/reset happens here
plot3(app.UIAxes,target_init_x,target_init_y,0,'kv',...
    'MarkerSize',20,'MarkerFaceColor',0.5*[1 1 1])
hold off

Answer 1

[Image Analyst]

Is it possible your missile and target coordinates are exactly overlapping? Or are in line with each other from that point of view so that you see only the closest one? Do you see both if you rotate the axes? This seems to work fine:

missile_init_x = -1000;
missile_init_y = -1000;
missile_init_alt = 2000;
target_init_x = 1000;
target_init_y = 1000;
hold on
plot3(missile_init_x,missile_init_y,...
    missile_init_alt,'ko','MarkerSize',15,'MarkerFaceColor',...
    'r') % <--------- Some form of clear/reset happens here
plot3(target_init_x,target_init_y,0,'kv',...
    'MarkerSize',20,'MarkerFaceColor',0.5*[1 1 1])
grid on;
view(500, 500)
hold off

[James Floyd]

That works in regular MATLAB, but in the GUI, it doesn't which is the most confusing part of all of this.