OpenGL fixed spot map glitch - c++

Question

I developed a game using OpenGL and c++, it all works fine but this glitch that I need to fix: when I move my camera around (using mouse) my map does not remain in a fixed spot.
It is basically a square (gl_quad) that I draw in front of me.
This is an example of the glitch:
Video
This is the drawing code of a square if it is needed
texture = scene->getTexture("map_papyrus.png");
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glUseProgram(this->shader->getRes());
glActiveTexture(GL_TEXTURE0);
GLint texture_location = glGetUniformLocation(this->shader- >getFragment(), "color_texture");
glUniform1i(texture_location, texture_location);
glBindTexture(GL_TEXTURE_2D, this->texture->getRes());
glBegin(GL_QUADS);
float size = .5f;
float offsetx = 0.0f;
float offsety = 0.0f;
if (set->easymode) { size = .2f; offsetx = 0.8f; offsety = 0.35f; }
glTexCoord2f(0,0); glVertex2f(-size + offsetx, -size + offsety);
glTexCoord2f(1, 0); glVertex2f(size + offsetx, -size +offsety);
glTexCoord2f(1,1); glVertex2f(size + offsetx, size + offsety);
glTexCoord2f(0, 1); glVertex2f(-size + offsetx, size + offsety);
glEnd();
glTranslated(0, 0, 0.00001);

Answer 1

Instead of rendering GUI elements as part of the 3D world, i'd rather finish drawing the world and then overlay on top of that a gui (without clearing the buffer).
That way the HUD doesn't need to move based on the camera's position and rotation.
Also, HUD elements wont clip with the world.
glClear(...)
// Scene:
glPushMatrix()
glPerspective(...)
glTranslatef(...)
glRotatef(...)
glBegin(...)
// ...
glEnd(...)
glPopMatrix()
// UI:
glPushMatrix()
glOrtho(...)
glBegin(...)
// ...
glEnd(...)
glPopMatrix()
// Swap buffers