When I made these changes the problem with loosing my meshes spread to the tracks. The sockets remained parented, but the reference to the track mesh was deleted. This happens between recompiles and when I close the editor. The tank also stopped moving. I added log messages to make sure the relevant functions were being called. They were, so something else obliviously changed. I have lost hte track meshes before, but removing the tracks and adding them back usually fixes the issue.
The projectile blue print being cleared in the aiming component has also returned. I suspect this is some sort of race condition, but it could be version differences with the engine, but either way it is an uphill fight to fix the issues that are occurring as changes are made to the project.
I am going to abandon this tutorial, but might revisit it in the future