The Xamarin Mono team introduced a breaking change in their SslStream implementation. This issue causes deadlocks if BeginRead and BeginWrite are called in parallel, which in turn causes connections to fail to connect on IceLink Xamarin clients. The Xamarin Mono team is aware of the issue and they have already merged a fix candidate. However, even though the fix has been merged, customers could still encounter this issue until the fix is released and they have had a chance to update. We know that the issue exists in Mono 18.104.22.168, but it may also affect other versions.
The IceLink 3.8.1 release, currently targeted to next week, introduces a work around which solves the issue regardless of the underlying Mono version.
Here is the Mono team's ticket for this issue:
And here is the fix from the Mono team: