This bug can be fixed by deleting the expression:

  ,(lambda (comp)
     (string-prefix-p minibuffer-default comp))

from icomplete--sorted-completions.

But it’s obviously there for some reason, so idk.

> On Jul 4, 2020, at 2:35 AM, João Távora <joaotavora@gmail.com> wrote:
> 
> Schwartzmeyer <andrew@schwartzmeyer.com <mailto:andrew@schwartzmeyer.com>> wrote
> 
> > Any clue?
> 
> I'm sorry Andrew haven't had time to look into it yet, but your analyses help.  Just note that Fido-mode is indeed geared primarily to working with flex. But it should be customizable of course.
> 
> João