Hey there @Mr.SEAL15! Lumen is able to do full Global Illumination(GI), but if the object is misconfigured somehow it may fallback to screen space only.
Changing to detail mode in your settings may help at the cost of performance:
I would recommend checking the Lumen visualization:
If your objects are black like these (this example is because they are far away but if they are black up close in the visualizer there is a problem, possibly with your imported mesh not having mesh distance fields enabled):
Sources for some of the information gathered here:
