Admin template is ignored when deploying - django-templates

Question

I have a strange situation here using Django 3.2.8:
When deploying, only one admin template is being ignored (but not if debug == True):
This is my directory after deploying (and before, they are identical):
change_form.html is applied correctly, whilst submit_line.html is not when debug = false.
content of change_form.html:
{% extends "admin/change_form.html" %}
{% load i18n admin_urls %}
{% block inline_field_sets %}
{% for inline_admin_formset in inline_admin_formsets %}
{% include inline_admin_formset.opts.template %}
{% endfor %}
<h3>
<p>WARNING!</p>
</h3>
{% endblock %}
content of submit_line.html:
{% load i18n admin_urls %}
<div class="submit-row">
{% if show_save %}
<input type="submit" value="{% trans 'Save' %}" class="default" name="_save" />{% endif %}
{% if show_delete_link %}
{% url opts|admin_urlname:'delete' original.pk|admin_urlquote as delete_url %}
<p class="deletelink-box">{% trans "Delete" %}</p>
{% endif %}
{% if show_download_zip %}
<input type="submit" value="{% trans 'zip' %}" name="_download_zip" />
{% endif %}
{% if show_save_as_new %}
<input type="submit" value="{% trans 'Save as new' %}" name="_saveasnew" />
{% endif %}
{% if show_save_and_add_another %}
<input type="submit" value="{% trans 'Save and add another' %}" name="_addanother" />
{% endif %}
{% if show_save_and_continue %}
<input type="submit" value="{% trans 'Save and continue editing' %}" name="_continue" />
{% endif %}
</div>
pre-deployment, with debug = True:
compares to:
Edit:
A little further digging:
When moving the logic from submit_line.html to change_form.html I get my download button, but only after setting all the buttons visibility by hand - again, this only happens when DEBUG == False:
working render_change_form from admin.py code fragment:
def render_change_form(self, request, context, *args, **kwargs):
context.update({'show_save_and_add_another': True})
context.update({'show_save_and_continue': True})
context.update({'show_save': True})
context.update({'show_delete_link': True})
if not context["original"] == None:
context.update({'show_download_zip': True})
return super().render_change_form(request, context, *args, **kwargs)
working change_form.html:
{% block submit_buttons_bottom %}
{% load i18n admin_urls %}
<div class="submit-row">
{% if show_save %}
<input type="submit" value="{% trans 'Save' %}" class="default" name="_save" />{% endif %}
{% if show_delete_link %}
{% url opts|admin_urlname:'delete' original.pk|admin_urlquote as delete_url %}
<p class="deletelink-box">{% trans "Delete" %}</p>
{% endif %}
{% if show_download_zip %}
<input type="submit" value="{% trans 'zip' %}" name="_download_zip" />
{% endif %}
{% if show_save_as_new %}
<input type="submit" value="{% trans 'Save as new' %}" name="_saveasnew" />
{% endif %}
{% if show_save_and_add_another %}
<input type="submit" value="{% trans 'Save and add another' %}" name="_addanother" />
{% endif %}
{% if show_save_and_continue %}
<input type="submit" value="{% trans 'Save and continue editing' %}" name="_continue" />
{% endif %}
</div>
{% endblock %}
When doing the same in DEBUG == True, the context.update()'s are not needed, also django uses the correct submit_line.html template without any issues.
So ... now I know how to fix this, but I can't figure out why this is happening the way I observed it.