Weird lighting glitch issue?

Hello everyone!

So I’ve been developing a map for about a couple weeks now, it’s roughly 10k x 10k in stud size. But I’ve recently encountered this odd lighting issue:

Is this something I specifically have done? Or is this just ROBLOXs engine taking a bathroom break. Please let me know, I would like to fix this as soon as possible.

This happens when your graphic quality is low in the main game. Try upping it.

or: I have this problem a lot. it is a glitch Roblox need to sort out them self


Thanks, I just had to restart studio. My graphics are always at max.