Django after migration UndefinedColumn error in production - django

Question

I have a website in production. I have an app, with a model. It contained a markdown_file attribute:
markdown_file=models.FileField(upload_to='/media/')
But since the number of file is limited, I decided to make it a markdown_filename attribute with a choices selection box:
markdown_filename=models.CharField(max_length=30,null=True,blank=True,choices=MENU_MARKDOWN_FILE_CHOICES)
Therefore, I modified this model and made migrations locally. I pushed the code in production and run:
python manage.py migrate
After I checked with showmigrations and sqlmigrate, that the modification I made were there. Then, I checked in the database, that the fields were correctly modified. But, I still get this error, when trying to access the website:
ERROR:django.request:Internal Server Error: /
Traceback (most recent call last):
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
psycopg2.errors.UndefinedColumn: column showcase_subpage.markdown_file does not exist
LINE 1: ...bpage"."slug", "showcase_subpage"."html_content", "showcase_...
^
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
response = get_response(request)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "./showcase/views.py", line 10, in home
return render(request, 'showcase/home.html', context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/shortcuts.py", line 36, in render
content = loader.render_to_string(template_name, context, request, using=using)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/loader.py", line 62, in render_to_string
return template.render(context, request)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/backends/django.py", line 61, in render
return self.template.render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 171, in render
return self._render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 163, in _render
return self.nodelist.render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 937, in render
bit = node.render_annotated(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 904, in render_annotated
return self.render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/loader_tags.py", line 150, in render
return compiled_parent._render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 163, in _render
return self.nodelist.render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 937, in render
bit = node.render_annotated(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/base.py", line 904, in render_annotated
return self.render(context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/template/defaulttags.py", line 166, in render
len_values = len(values)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/models/query.py", line 256, in __len__
self._fetch_all()
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/models/query.py", line 1242, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/models/query.py", line 55, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 1100, in execute_sql
cursor.execute(sql, params)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/backends/utils.py", line 67, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/backends/utils.py", line 76, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/srv/data/web/vhosts/default/local/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: column showcase_subpage.markdown_file does not exist
LINE 1: ...bpage"."slug", "showcase_subpage"."html_content", "showcase_...
^
The markdown_file field has been modified and renamed as markdown_filename. It has been correctly specified in the migrations. The modification is effective in the database. I tested locally (it works fine locally), to make sure, I don’t have anymore code calling markdown_file attribute.
I also tried clearing the migrations history and the database, to rebuilt it as new, but, the problem is still there. I can’t see why, this former attributes is still queried, though the migrations went OK, without any error.