for some reason the other lights aren't visible in the geometry and mains views, but there is a workaround but would be great to have it working thnaks.
I use a PC Win 10 64 bits home, 128Go Ram, RTX3080Ti, i9 CPU and latest version 11.1.0 Pro of Keyshot
Follow thèse steps:
1. create a new project
2. create a plane
3. doble click and make the material Area light
4. observe how the Area light is displayed in both main view and geometry view
5. now change the light to Spotlight
6. light disappears in both main and geometry view
6. as a workaround you can do this, copy the material from this plane and paste it to the same plane again
7. now the light is visible again.