Work through these in order:

1. Check the plugin is actually producing colour. Open Ambient Lights → Capture Settings and look at "Live output per light" at the bottom. If you see changing RGB numbers, DNR is working and the problem is downstream (steps 2–3).
2. Test the light from SimHub directly. In SimHub's own Ambient Lights page, use its built-in test/preview to flash your light. If it doesn't respond even there, it's a connection/pairing issue with the light itself (e.g. Hue bridge), not DNR.
3. Re-import the DNR light profile. In SimHub's Ambient Lights → Color effects, make sure the "Daniel Newman Racing – Ambient Lighting" profile is selected and up to date. Re-importing it fixes cases where an old profile stops the colours coming through.