I have a MacCatalyst app that is published on the Mac AppStore. All seems fine and dandy on the released version.
However, when I try to test a build on my Intel based Macbook using the TestFlight app it says it's not compatible.
I've looked at the build on AppStore connect and I can see that it's a universal build with x86_64, arm64 architectures.
I'm at a loss as to why Test Flight reports it as incompatible yet the Mac App Store says it is compatible.
Update, hopefully this helps if anyone comes across this with the same problem.
TestFlight was only showing me the iOS version of the app in the UI which is why it wasn't compatible. It was showing me the option as iOS app can be tested on a Mac with Silicon chip.
What I needed to do is resend the invitation to myself and accept it from the email. It then showed me the Mac version and gave me the option to install it.
Possibly a schoolboy error but I think TestFlight is "supposed" to show you apps you are invited to test regardless of an email. But maybe not, I could be wrong there.