My blf-text appears in all 3d viewports after specific actions (ex selecting)

Question

I noticed that the moment I select or deselect an object my blf text appears in all 3d viewports: is there something wrong with he way I use drawback handler?

Here's a gif with the issue:

Here's my simple modal:

import bpy
import blf

def draw_text(text, size, x, y, font_id, dpi, color=(1, 1, 1, 1)):
    blf.size(font_id, size, dpi)
    blf.color(0, *color)
    blf.position(font_id, x, y, 0)
    blf.draw(font_id, text)

def draw_callback_px(self, context):
    blf.enable(0, blf.SHADOW)
    blf.shadow_offset(0, 2, -2)
    blf.shadow(0, 3, 0, 0, 0, 1)

    draw_text(self.status, 30, 50, 115, 0, 72)
    draw_text('My Modal', 30, 50, 150, 0, 72)

class ModalOperator(bpy.types.Operator):
    """test"""
    bl_idname = "object.modal_operator"
    bl_label = "Simple Modal Operator"

    def modal(self, context, event):
        context.area.tag_redraw()
        
        if event.type == 'MOUSEMOVE':
            pass

        elif event.type == 'LEFTMOUSE' and event.value == 'RELEASE':
            for ob in bpy.context.view_layer.objects:
                ob.select_set(False if ob.select_get() else True)
            self.status = 'Clicked'
                
            return {'RUNNING_MODAL'}

        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            if self._draw_handler:
                bpy.types.SpaceView3D.draw_handler_remove(self._draw_handler, 'WINDOW')
            return {'CANCELLED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        self.status = 'Not Clicked'
        if context.space_data.type == 'VIEW_3D':
            self._draw_handler = bpy.types.SpaceView3D.draw_handler_add(draw_callback_px, (self, context), 'WINDOW', 'POST_PIXEL')
        
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}


def register():
    bpy.utils.register_class(ModalOperator)


def unregister():
    bpy.utils.unregister_class(ModalOperator)


if __name__ == "__main__":
    register()