<a> element does not recognize the file extension automatically when downloading a file

I'm currently developing an application where the user clicks on an element, that element calls a JS function and the function handles a file download.

The files are reports generated dynamically by Devexpress XtraReports module, converted to Base64 and then sent back to the client side. When the client receives the Base64 string, the JS function creates an <a> element, sets the href attribute to data:application/pdf;base64,JVBERi0xLjQNCiWio[...] and simulates a click with the click() event.

Here's the piece of JS code that handles the file download:

let downloadLink;

    try {
        downloadLink = executionId ? await getLinkPdfBase64(executionId) : false;
    } catch (error) {
        downloadLink = false;
        console.log(error);
    }

    if (downloadLink) {
        const aElement = document.createElement("a");
        downloadLink = "data:application/pdf;base64," + downloadLink;
        aElement.setAttribute("download", currentReportData.LayoutName);
        aElement.setAttribute("href", downloadLink);
        aElement.click();
        aElement.remove();
    } else {
        DevExpress.ui.dialog.alert( //Ignore this, it's a Devexpress component
            "Your report could not be generated",
            "Alert"
        );
    }

The problem is:

When I generate a report with custom parameter types, Devexpress generates it correctly (the Base64, if converted to string, is visibly correctly formed) but the browser (Google Chrome) downloads the file with the extension ".0".

If the report has normal Devexpress parameters (like Strings, Int32, Guids, etc)) the file is downloaded with the correct ".pdf" extension.

Here's a picture of a correctly downloaded PDF and a ".0" extension file:

Could it be the JS function the cause or the solution to the problem? If not, almost for sure there will be something wrong with the report generator (Devexpress).

NB: If I manually change the ".0" extension to ".pdf" the file opens and it is displayed / formed correctly.

Turns out I ended up solving it just by adding the file extension ".pdf" in the download attribute, so when the browser can't recognize it, you are already specifying which one it is:

aElement.setAttribute("download", currentReportData.LayoutName + ".pdf");