I think it is very much related to this bug as well:
You need a custom component (C++ class) and use it in your blueprint. By making changes to the custom component and doing HotReload, you will possibly experience this bug or one of the other bugs i’ve posted on this.
Hot Reload makes changed C++ classes unknown - Programming & Scripting - Unreal Engine Forums Cast fails if HotReload has changed component type - Programming & Scripting - Unreal Engine Forums How to reload config if editor is already open - Programming & Scripting - Unreal Engine Forums