That’s interesting, I had a similar experience when the notionally faulty parts replacement arrived. It behaved faultlessly until I changed it (why?), I then stripped the “old” part to see what was adrift, could see nothing & whilst reassembling it a part jumped ship & has never been seen or heard of since.
And the moral of this story is don’t bugger about with a dead end job when there’s more productive stuff to be done.