Installing UWP App Causes 0x800B0109 Error

I'm trying to install my own UWP app which I created in Visual Studio 2019 v16.1.1 and have packaged it for sideloading. I have been unable to install the application on my PC and my friends PC, both running the latest version of Windows 10.

I have tried all the methods, both on Microsoft's docs, forums as well as here. All have failed and the installation still produces the same error.

Including: Installing .appx without trusted certificate? How to create a working trusted and or self-signed certificate for a Windows 10 UWP application via Visual Studio 2019, 2017 and 2015

The error is

"Either a new certificate must be installed for this app package or you need a new app package with trusted certificates. Your system administrator or the app developer can help. A certificate chain was processed but terminated in a root certificate that isn't trusted (0x800B0109)"

The error received is 0x800B0109.