RadzenUpload not working

I have build a server side blazor app, where I have used a filemanager generated based on this blog:

However, suddenly my RadzenUpload function:
<RadzenUpload ChooseText="Upload Files" Multiple="true"
Style="margin-bottom: 20px;height: 45px"
Progress="@((args) => OnProgress(args))" />
doesn't upload files, but instead throws an error: Uncaught SyntaxError: Invalid Unicode escape sequence
I have recently updated to Radzen.Blazor 3.0.3, I tried downgrading to 2.18.10, but that didn't fix the issue.

I am using windows 10, and Chrome browser.

Is there an easy fix for this?

You have most probably backslash in this variable value.

It seems, that it works when I use Radzen.Blazor version 2.0.2 even with the backslash.

If I change the backslash to a forward slash, I don't get an error, however the files are not uploaded.

Is Radzen compatible with dotnet 5.0?

Our demos are exactly .NET 5.