Time out - Null Bytes error when trying to upload to the Windows Store

I hoping to find some assistance here or a work around. I'm trying to upload my first app to the windows store, I feel like I've come all of this way in the development and now I'm stuck just behind the finish line.

I have read every document I can find and tried every combination of settings I know of and I still cannot get my msixupload to properly upload into partner center correctly. The rejection dialog I receive is attached. I'm going to try to attach as much information here as I can in hope someone will have an idea on what I can do differently?

I'm using VS 2026 and used the standard template for building a C# windows store app. My app has a WinUI interface.

I am able to successfully link to my app in partner center to generate the manifest.
I then package the application through the create package dialog.

Here is the WACK test results

msixupload file

And when I try to upload to Partner Center this is what I get no matter what I try, I can not get past this point.