Thank you for your report! We would like to look into this further, would you be able to submit a bug report using the form available here: Fortnite Creative
I found that the cause of this problem was in the canvas generation logic. I performed the canvas generation on the instance of the class generated on the device. While it initially works, it eventually stops functioning. This is likely because the class instance on the device is incompatible with the UI generation logic.
I don’t believe it is the circular reference problem mentioned above.