Ever since the recent update of 2.29i, with the major lighting overhaul, indoor areas are seemingly being affected as well by it. As the day progresses, the lighting will change to affect it as if you were outdoors. I cannot find any common reason why or how, only that it seems to be client side and will cycle itself if you
enter and leave again whenever.Below is an example of The Lady's Rest.
Lighting being affected:

Entering again randomly some time later, back to normal:

This seemingly effects
any indoor area I've noticed. I've seen it in other buildings and dungeons. I cannot discern a cause or reason.