After migrating from Dotnet8 to Dotnet9 for out iOS application our ShareSheet extension no longer works

Question

We have a cross platform app written in DotNet (initially it was a Mono app, so there is history in this app). One part of the app is a share sheet extension so that the user can add invoices sent to them via email to the system.

We have noticed that as soon as we updated the app to DotNet9 the share sheet fails to load when instantiated from the mail client.

We also have another app that has an share extention that also fails when migrating to version 9 of DotNet.

Is there anything we need to add to the share sheet project to make it work with dotnet 9

We can't see why it fails because we have been unable to debug the code since we ported it from Dotnet4 to dotnet core (dontnet6)