Lighting level not resetting

light level raised by redstone lamps was not properly resetting when lamps were switched off.

In both instances where I reproduced the bug I was in the nether within range of a monster spawner. (although this may have just been coincidence as the light level bug seemed to be focused only on certain blocks.)

the light level can be reset to 0 by re-logging the world. but returns when the lamps are toggled

included are screenshots of the issue [21.41.21], the (correct) light level after re-logging [21.42.32], and while redstone lamps are active [21.42.37].
Also inclueded is a wider view of the effect [21.41.49]

I tryed 3 more times to reproduce the issue in differn't locations/ worlds. one was sucessful (screenshot 21.56.40).

World seed was -216290396724398692
Co-ordinates are in the screenshots.