Wagtail render StreamField which comes from ParentalLkey

I am trying to render StreamField which is located in OrderaBle class And has a ParentalKey.

I can easily access every value from StreamField with for loop in items, but what i want is the following:

I want to loop through the blocks for e.g : {% for block in page.submenu %} (or self.submenu)

But when i am trying to do it i am getting nothing, so it seems i can't access blocks because of ParentalKey i think.

from django.db import models
from django_extensions.db.fields import AutoSlugField
from modelcluster.fields import ParentalKey
from modelcluster.models import ClusterableModel
from wagtail.admin.edit_handlers import (
    MultiFieldPanel,
    InlinePanel,
    FieldPanel,
    PageChooserPanel,
    StreamFieldPanel
)
from wagtail.core.fields import StreamField
from wagtail.core.models import Orderable
from wagtail.snippets.models import register_snippet
from streams import blocks
from wagtail.core.models import Page



class MenuItem(Orderable):
    link_title = models.CharField(blank=True, null=True, max_length=50)
    link_url = models.CharField(blank=True, max_length=500,)
    link_page = models.ForeignKey("wagtailcore.Page", null=True, blank=True, related_name="+", on_delete=models.CASCADE)
    link_target = models.BooleanField(default=False, blank=True)
    
    
    # thirdmenu = StreamField([ 
    #         ("thirdmenu", blocks.MenuBlock())
    #         ],
    #         null=True,
    #         blank=True
    #         )
    
 
    
    page = ParentalKey("Menu", related_name="menu_items")
    
    
    submenu = StreamField([ 
            ("menus", blocks.MenuBlock()),
            ('thirdmenu', blocks.ThirdMenuBlock())
            ],
            null=True,
            blank=True
            )
    

    panels = [
        FieldPanel("link_title"),
        FieldPanel("link_url"),
        PageChooserPanel("link_page"),
        FieldPanel("link_target"),
        StreamFieldPanel("submenu"),
        # StreamFieldPanel("thirdmenu")
        
    ]

    @property
    def link(self):
        if self.link_page:
            return self.link_page.url
        elif self.link_url:
            return self.link_url
        return '#'

    @property
    def title(self):
        if self.link_page and not self.link_title:
            return self.link_page.title
        elif self.link_title:
            return self.link_title
        return 'Missing Title'
    


@register_snippet
class Menu(ClusterableModel):
    title = models.CharField(max_length=100)
    slug = AutoSlugField(populate_from="title", editable=True)
    

    panels = [
        MultiFieldPanel([
            FieldPanel("title"),
            FieldPanel("slug"),
        ], 
            heading="Menu"),
        InlinePanel('menu_items', heading="Menu Items"),


        

    ]

    def __str__(self):
        return self.title
    
    
    

{% load wagtailcore_tags %}
{% load static %}
<header>
   <div class="navbar-container">
   <nav class="navbar navbar-expand-lg navbar-light">
   <div class="container">
   <a class="navbar-brand" href="/">
      <img src="{% static 'assets/logo.svg' %}" loading="lazy" alt="Codely Logo" class="nav-logo-img">
      <div class="nav-name">Vetsch<br>Gebäudehüllen</div>
   </a>
   <button class="navbar-toggler" type="button" data-bs-toggle="collapse"
      data-bs-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false"
      aria-label="Toggle navigation">
   <span class="navbar-toggler-icon"></span>
   </button>
   <div class="dropdown">
      {% for item in menu.menu_items.all %}
      <a class="nav-item" href="#" role="button" id="navbarNavDropdown" data-bs-toggle="dropdown" aria-expanded="false" style="color: #333333"> 
      {{ item.title }}
      &nbsp; 
      &nbsp;
      &nbsp;
      </a>
      <ul class="dropdown-menu" aria-labelledby="dropdownMenuLink">
         {% for block in page.submenu %}
            {{ block.title }}
            <ul class="dropdown-menu dropdown-submenu">
               {% for b in i.thirdmenu %}
               <li>
                  <a class="dropdown-item" href="{{ b.page }}">{{ b }}</a>
               </li>
         {% endfor %}
               </li>
            </ul>
               {% endfor %}           
      </ul>
      {% endfor %}
   </div>
</header>