How to turn off fuzzy selection mask?

[rich2005]

A selection does not survive a Select -> None  (shift-ctrl-a) Reinstalling Gimp is never a solution where the problem is the workflow. An active selection is saved in Gimp .xcf format, that is the only way it shows straight away when an image is re-opened.  From the screenshot, the selection originally came from a different layer. Is that pattern "hard-baked" into the image, maybe on one layer.

More information please. Post a screenshot showing layers and tools like this

   

or if you have the .xcf file, post that.