A few days after epoxying a replacement WS2812 RGB LED into the base of the 21HB5A and, en passant, soldering a 3.5 mm plug-and-jack into the plate lead for EZ removal, the top LED failed.
In this case, it also failed the Josh Sharpie test with bad encapsulation sealing:
Here’s a view from another angle, with a warm-white desk lamp for a bit of color:
Those patterns took a few days to appear and also showed up in some, but not all, of the previous failing LEDs.
Although I have no idea what’s going on, it’s certainly distinctive!
An envelope of RGBW LEDs, allegedly with SK2812 controllers, has arrived from a different eBay supplier, so it’s time for an upgrade.