WLED sometimes doesn’t turn off on timer...?

I have a small WLED project; it’s a scale model lit with LEDs that I want to light up every night from around 8pm til we go to bed around midnight.

To this end, I set up the lighting as I wanted and saved it as a preset, then I set a schedule for that preset to become active at 8pm and another preset with all the lights fully off to activate at midnight. Most nights this system works flawlessly.

The problem is, when I wake up in the morning sometimes the lights are still active, and some mornings the lights are incredibly dim as if they’re at 10% brightness, but still active. Some mornings it works perfectly, and there doesn’t seem to be any rhyme nor reason to which nights the timer function works correctly or not…

Has anyone else experienced this kind of discrepancies or figured out why it’s sporadically failing?