lost corks

On rather small areas, the particular contact glue becomes more fussy. So does the thickness of glue that is applied, Too thick, or inappropriate glue, and the result is a cork that rather easily "slimes" its way off the key.

Also, it is difficult to do a good, thin, even application of glue without removing the key.

Always, how a material is used is just as important as the material itself.

I have also found superglue - done by others... I don't use it - to be less reliable, usually parting from the metal.
Reason? Hmmm. It is possibly a lot more fussy about surfaces being uncontaminated with any trace of oil or grease.