Its not always just Chinese "clones" that have problems.
Back in the 1990s, I had to pull apart an "in house" made TV transmitter remote controller to change the operating method of one of the emergency programme sources.
Part of this device used a couple of National Semiconductor monostable ICs to provide longish delay times.
Whilst playing with the unit, I dropped, & lost, one of the monostables-------------bummer!
No problems, though, plenty in the store.
I grabbed one, checked the operation---------suddenly, it kept timing out early, so the controller function didn't work any more.
I borrowed the IC from one of the other functions, & all was well, but when I tried the function the new one was swapped to, it too, failed to work as designed.
Must be a bad IC, let's just grab another!
After 4, it became obvious that the new devices had a problem the originals did not have.
Much research followed----no Google back then, just digging through books.
It turned out that NS had been getting complaints that the mono wasn't reliable for short time intervals, so they redesigned it.
The problem was, it now didn't work properly for long intervals, so they re-released the original IC under a new part number.
We had made just two of these controllers, so it wasn't a major drama ---------we just bought a stock of the new part number ICs, changed the documentation to reflect this, & were good to go.
Imagine if we had been a manufacturer with tens of thousands such units out "in the wild"!