The collection system is a blessing, and everything is logical; but as I switch between my main collection through numbers (1,2,3,…) in rendered mode, or when I switch to local view (/), or hide the rest of the scene (Shift+H), I always end up with this light-off effect that forces me to switch the light back on. I understand why it is difficult to avoid in local view
and Shift+H view, although I’d really like to have an option therefore; and I chose to put the lights in the main collection to keep them on when I switch between the main layers. As the rendered view becomes available as a working environment in Eevee; finding a way to extract the lights from the visibility matters would be very handy. My eternal gratitude to the problem solver, if born he/she is.
See this post on several forums: