My tub was draining slowly, so I removed the drain cover stopper and reached down into the drain with needle-nose pliers and extracted a disgusting wad of hair and soap residue, as I have done several times before.
However, this time it didn't solve the issue, so I got a drain snake and fed it down into the drain, but it did not extract any further clogs. And on my next shower, the tub drained much more slowly. I made the problem worse!
I thought I would have to call a plumber. As a last resort I watched a few do-it-yourself videos on YouTube, and one of them showed removing the overflow plate and feeding the drain snake down that way, instead of the actual drain. So I tried that, and lo and behold, it brought out another fat disgusting hair clog.
Why did snaking the overflow plate work, when the actual drain didn't?