There are random sources of light in the world

In my Survival Realm world, I've built a relatively large hall. Around the hall, there are rooms that are approximately 20 x 10 x 7 blocks in size. It keeps happening that lighting glitches occur in these rooms. For instance, the small rooms are completely bright, even though there are only a few torches there, which could never illuminate the space that much. And in the large hall, it often happens that, for example, half of the hall is completely lit up, even though there are sometimes no torches there at all 

As soon as I leave the realm and rejoin or unload and then reload the chunks, the lighting bugs disappear completely. However, sometimes they reappear after re-entering the realm.

I know there's already a bug report regarding the lighting issues, but it was marked as resolved even though the lighting bugs persist. I'm not sure how else to highlight that the bug is still present besides making this new post here.
 
I recreated the bug in a new world with the same seed.

I have attached the affected world below. I've set my render distance to 21 chunks. I'm not sure if the lighting bugs appear there when teleporting, but so far, they always appeared for me when I walked towards the hall from a bit farther away, causing the chunks to load.*
The screenshot shows how one half of the hall is completely brightly lit without any apparent reason. Sometimes, the bug also occurs on the second side.