MQTTnet/.github/workflows/ReleaseNotes.md

• [Core] Fixed several dead locks by implementing a new async signal (#1552)
• [Client] All waiting tasks will now fail when the client connection gets closed. This fixes several freezes (#1561)
• [ManagedClient] The topic is no longer declared as invalid if a topic alias is used (#1395)
• [Server] Fixed duplicated invocation of the event ClientAcknowledgedPublishPacketAsync for QoS level 2 (#1550)
• [Server] Fixed issue in upgrading and downgrading of QoS levels for subscriptions and retained messages (#1560)
• [Server] Fixed memory leak when old sessions are discarded (#1553)
• [Server] When using MQTTv5 the reason code NoMatchingSubscribers is returned when no client is subscribed to a published topic (#802)
• [Server] Fix sending of duplicate messages with QoS > 0 when session is recovered and session is reused (#1546)