Some chunks in a line are lit up constantly

I only ran into the opposite so far, where the affected area has a Client Light level of 0; in this case, presumably the affected area will have a light level of 15.

What is your gamma value set to?

What does Plausible mean? (on the bug tracker)

Means that it can be true or not, like they are just waiting to see if this can be reproduced

@unknown Plausible, probably - as I wrote here - the opposite happens comparably often, thus there's some probability that the opposite can happen as well.
I haven't run into this yet, still searching.

I experienced this issue when creating and exploring around a superflat world today.

@unknown Could you please give more detailed reproduction steps? Which type of Superflat, what were your world specs, maybe also video settings or the likes?

@unknown, sure! I used a default Superflat world. I used Fancy graphics, Fancy clouds, and everything else was default. I used a MacBook Air with the M1 chipset when I experienced this issue. Unfortunately, I don't have any reproduction steps, as I'm not sure what is causing the issue. If you'd like any more information, I'll gladly provide it.

I doubt video settings is causing the issue.