First, It is impossible to open a ticket at Github for the “Apps” application. IMO, all projects should allow the community to open issues, and even propose PRs.
Second, when using Blokada (which is in essence a DNS filter run over a local VPN) it is impossible to install or update an application using the “Apps” app. When using Blokada, the Apps app will tell you when you need to update something, but when you click on install, the file refuses to download. As soon as you turn off Blokada, the app downloads and install properly.
I note that Blokada is not blocking any DNS inquiries from Apps (nothing shows up in the list), so I suspect that the problem is related to the fact that a VPN is running.
We stopped raising issues in individual project some time back. All issues are raised in one place and then we label and mark them to fall under different categories or projects.