Unofficial DMX in Unreal MegaThread. 4.26+

I have written in Blueprints a DMX Analysis project. The project was in v4.26 Preview 4 where it was working fine. Upgrading to preview 5 broke it. This happens on both macOS and Windows. In the level blueprint I bind to the On Protocol Received event and it appears that this event is no longer being triggered. I have tried just attaching a PrintString node to the execute pin of the event and it is not being triggered. Interestingly, the DMX Channel Monitor is showing received DMX correctly. Is anyone else seeing anything similar ?