I was able to setup a release test for an iOS app for distribution using a web server. It works perfectly fine for all the devices I registered for the deployment profile.
However every time I try to distribute a Unity based Vision Pro application using the same process for building the package and set up for distribution it does not work. Safari only shows a message telling me: "Cannot connect to <my url>." When trying to install the iOS app from the same server it shows the message "Do you want to install <my app>?" and installation completes correctly.
My iOS is a simple hello world app generated by Xcode. My Unity app is an AR app targeting com.apple.platform.xros.
According to documentation there should not be any difference in deployment profiles/signing for iOS apps vs. visionOS apps.
What am I doing wrong? Any hint is appreciated how to continue.