I've had a similar problem, I've also got half a dozen floppy drives. I cleaned the heads in all of them with a good solvent and managed to get one working, but then all of a sudden it stopped again!
I usually get DF0:

? when I insert a floppy once WB has loaded, rarely I get a DF0:NDOS, and extremely rarely I get a disk loading but with loads of read errors.
Today I received a Gotek, but I'm struggling to get it to work... :/