October 2021 Update
We have updated our applications to be built gainst ios SDK 14.5 and have made the same tests on ios 15 devices. The problem is still there. The second application does not trigger the local network permission prompt
I have two in house xamarin.ios applications build against ios SDK 11.2 When i try to install the first application on a device running on ios 14 i see the prompt message asking the user for permission to access the Local Network. However, if i grant access and try to install the second application it never asks again with a consequence the second application to fail in all network calls
From iOS 14.2, the app is correctly triggering the network privacy alert after an upgrade , full deletion and reinstall. Recommend you to upgrade to 14.2 check if it is works now.