Thanks for reaching out. When you say "the “Trace” function”, I am reading this as you intend to have the laser travel the boundary of this project, with the beam off, to check alignment on your material. Do I have that correct?
If yes, we refer to this functionality as “Framing”. 
To assist with tracking down what you are observing and why, it might be faster if you can document / provide video and images with illustrations, showing us what you “see”. Include several screenshots of LightBurn, showing the full screen, your settings for each layer and tab used for this project. Also share the OS and version number for LightBurn.
Out of curiosity, have you tried running this job using RDWorks, the software that comes with the Ruida motion control system in your laser? This could help in troubleshooting hardware vs software.
This way, we can review all relevant information at once, while trying to assist in resolution. 