Having started replacing the fluorescent shop lights with LED tubes back in 2016, this was only a matter of time:
The next morning the dead section lit up again, albeit with a dim ring at its right end. I think one LED in that string failed open and darkened the whole string, then failed short under the voltage stress, and is now quietly simmering in there with slightly higher than usual current.
The lights over the workbench weren’t in the first wave of conversions, so they may be only four years old.
For sure, they have yet to approach their 50000 hour lifetime …
The Smell of Molten Projects in the Morning 
I have to be careful with my converted shoplights. Some tubes need power at both ends (and both pins on each side must be powered) while the other set needs power at one end. I don’t use the ballast type, since I’ve had terrible luck with shoplight ballasts.
Sharpie notations on the lights for the win.
I feel your angst! Mad Phil gave me his Brother label printer, so my conversions sport
Line/Neutral/LED Tubes Onlylabels in bright red / yellow / green.Even knowing the tombstone sockets had two isolated pins, the “power at one end” LED tubes still scared me and I knew if I had both kinds I would eventually make a spectacular error.