Swagger UI uploads empty CSV (latin1 encoded)

Swagger UI uploads empty CSV if it is latin1 encoded (csv has danish characters like ø, Ø, Æ), works alright with standard utf-8 encoded CSV.

Here is swagger json:

{
  "swagger": "2.0",
  "info": {
    "version": "2.2",
    "title": "searcher"
  },
  "paths": {
    "/search": {
      "post": {
        "summary": "Search endpoint uploading files manually",
        "tags": [
          "Calls"
        ],
        "consumes": [
          "multipart/form-data"
        ],
        "produces": [
          "text/csv"
        ],
        "parameters": [
          {
            "name": "reference_file",
            "in": "formData",
            "type": "file",
            "required": true,
            "description": "CSV file containing reference data"
          },
          {
            "name": "query_file",
            "in": "formData",
            "type": "file",
            "required": true,
            "description": "CSV file containing query data"
          },
          {
            "name": "config_file",
            "in": "formData",
            "type": "file",
            "required": true,
            "description": "JSON file containing configuration data"
          }
        ],
        "responses": {
          "200": {
            "description": "Successful response",
            "schema": {
              "type": "string",
              "example": "type,similarity,id,name,surname,age,gender,region,date_payment,amount,id_reference,name_reference,surname_reference,age_reference,gender_reference,region_reference\nsimilar_id,0.9999997,1771594086,Molly,Forsberg,50,male,Stockholm,43888,398.82,1771594087,Molly,Forsberg,50,male,Stockholm\nfeature_search,1.0000001,3519854485,Isak,Ek,25,male,Gotland,44797,819.62,3040728485,Isak,Ek,25,male,Gotland\nmatch,1,6919199375,William,Lundverg,35,male,Dalarna,43882,398.82,6919199375,William,Lundberg,35,male,Dalarna\n"
            }
          }
        }
      },
      "x-swagger-router-controller": "app"
    }
  }
}

here is the python code that tries to read a file identified with 'query_file' in wagger json:

from flask import request
@app.route('/search', methods=['POST'])
def seas_query() -> Response:
    try:
        filename = 'query_file'
        df = pd.read_csv(request.files[filename], sep = ',', dtype = 'object')
    except UnicodeDecodeError:
        print('Unable to read {fname}, trying with latin1 encoding.'.format(fname=request.files[filename]))

        file_obj = request.files[filename]
        file_obj.save('downloaded_'+file_obj.filename)
        # even the downloaded file from above code is empty
        df = pd.read_csv('downloaded_'+file_obj.filename, delimiter=";", encoding='latin1')
    except Exception as e:
        print('Unable to read file')

the exception I receive is:

df = pd.read_csv('downloaded_'+file_obj.filename, delimiter=";", encoding='latin1')
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ore\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.11_qbz5n2kfra8p0\LocalCache\local-packages\Python311\site-packages\pandas\util\_decorators.py", line 211, in wrapper
return func(*args, **kwargs)
...
...
...
File "pandas\_libs\parsers.pyx", line 554, in pandas._libs.parsers.TextReader.__cinit__
pandas.errors.EmptyDataError: No columns to parse from file

The csv has data inside it. Also, loads data fine when I use utf-8 encoded csv or any other csv that doesn't contain danish letters.