Javascript - CSV import UTF-8 encoding

I try to import a CSV file via javascript. But the encoding is wrong. "ä, ö, ü, etc." are probably imported with ANSI instead of UTF-8.

The CSV file is exported before by me, there I managed to set the encoding to UTF-8. But I fail to import it correctly. Can anyone show me how this import should be done?

To illustrate the current problem:

Export format:

Männlich;Sehr geehrter;Per Sie;Dr.;Jürgen;Böhler;[email protected]

Import format:

Männlich;Sehr geehrter;Per Sie;Dr.;Jürgen;Böhler;[email protected]

Export function

function csv() {

        const rows = [[geschlecht[0].value, anrede[0].value, umgangsform[0].value, titel[0].value, vorname[0].value,nachname[0].value,email[0].value ]];
        var universalBOM = "\uFEFF";
        var csvContent = '';
        rows.forEach(function(rowArray){
            let row = rowArray.join(";");
            csvContent += row + "\r\n";
            for (i = 1; i < titel.length; i++) {

                csvContent +=  geschlecht[i].value + ';' + anrede[i].value + ';' + umgangsform[i].value + ';' + titel[i].value + ';' + vorname[i].value + ';' + nachname[i].value + ';' + email[i].value + "\r\n";
            }

        });
        var link = document.createElement("a");
        link.setAttribute("href", "data:text/csv;charset=utf-8," + encodeURIComponent(universalBOM+csvContent));
        link.setAttribute("download", "export.csv");
        document.body.appendChild(link); // Required for FF

        link.click(); // This will download the data file named "export.csv".

    }

Import function

function readBlob(opt_startByte, opt_stopByte) {

    var files = document.getElementById('files').files;
    if (!files.length || !((files[0].name).endsWith(".csv"))) {
      alert('Bitte eine .csv-Datei auswählen!');
      return;
    }

    var file = files[0];
    var start = parseInt(opt_startByte) || 0;
    var stop = parseInt(opt_stopByte) || file.size - 1;

    var reader = new FileReader();

    // If we use onloadend, we need to check the readyState.
    reader.onloadend = function(evt) {
    if (evt.target.readyState == FileReader.DONE) { // DONE == 2
       document.getElementById('textareaMails').value += evt.target.result;
      }
    };

    var blob = file.slice(start, stop + 1);
    reader.readAsBinaryString(blob);


  }

  document.querySelector('.readBytesButtons').addEventListener('click', function(evt) {

    if (evt.target.tagName.toLowerCase() == 'button') {
      var startByte = evt.target.getAttribute('data-startbyte');
      var endByte = evt.target.getAttribute('data-endbyte');
      readBlob(startByte, endByte);

    }
  }, false);