Subdirectories searching are case sensitive, while parent directories are not

[ReneFroger]

Describe the bug
When I navigate to the first directory, my input is not case sensitive. But for the next subdirectory, it's case sensitive however.

To Reproduce

Imagine you are in the following home directory

/home/user
       ⌞ Foo
         ⌞ Bar

You call fifc, then type foo (first letter lower case).
Then you see directory Foo. as input. Press enter.

Then you have navigated to the directory Foo.

You call fifc again and type bar (first lower letter case).

But the directory Bar however doesn't show up because the input is lower case only, which is strange behaviour compared with how the first directory is looked up.

Expected behavior
I was expecting the same case-insensitive behaviour when filtering subdirectories like with the directories in same operation.

[ReneFroger]

I was wondering if you got any chance to look into this, perhaps, @gazorby ?