If particle emitter is dynamically created with non-particle system parent (e.g. null) and then reparented to a particle system, its system property will remain null, as it is automatically updated only during component completion.

Similarly, when you do not explicitly set the system property of an emitter to point to specific particle system, the system property will not update if the emitter is moved under another particle system as one would expect.

This issue causes newly added emitters to not work in Qt Design Studio until you reset the puppet or explicitly set the system property, and if you move them under another system, they will continue to behave like they are part of the old system until you reset the puppet.

Attached a simple test app to demonstrate the issue.