Export to HTML and CSV is not working properly

Export to HTML and CSV is not working properly.
When we are using export to HTML or CSV in the export tab is not working properly and it is bringing code instead of values. Export to Excel is Ok.
Below is the code we are trying:
function exportToExcel() {
flexmonster.exportTo('excel', {useCustomizeCellForData: false});
}
function exportToHtml() {
flexmonster.exportTo('html', {useCustomizeCellForData: false});
}
function exportToCsv() {
flexmonster.exportTo('csv', {useCustomizeCellForData: false});
}
 
function customizeToolbar(toolbar) {
    let tabs = toolbar.getTabs();
    toolbar.getTabs = function() {
    tabs = tabs.filter(tab => tab.id != "fm-tab-connect");
    tabs.unshift({
        id: "fm-tab-newtab",
        title: "Commit",
        handler: newtabHandler,
        icon: this.icons.save
    });
 
    let exportTab = tabs.find(tab => tab.id == "fm-tab-export");
    if (!exportTab) return tabs;
    let exportToExcelTab = exportTab.menu.find(tab => tab.id == "fm-tab-export-excel");
    exportToExcelTab.handler = exportToExcel;
    
    let exportToHtmlTab = exportTab.menu.find(tab => tab.id == "fm-tab-export-html");
    exportToHtmlTab.handler = exportToHtml;
 
    let exportToCsvTab = exportTab.menu.find(tab => tab.id == "fm-tab-export-csv");
    exportToCsvTab.handler = exportToCsv;
 
    return tabs;
    }