How to get TAB autocomplete to work? And general confusion over how to use

I was very excited to find this extension (I'm an old Emacs guy), I already like it much more than the standard VSCode file browser. But I am unclear how to get autocomplete to work. I also have the [vscode-emacs-mcx](https://github.com/whitphx/vscode-emacs-mcx) extension.

The workflow I am used to: Let's say I'm after a file called `file2.txt` in a directory containing `file1.txt`, `file2.txt` and `adirectory`)
* Ctrl-x-f to open file browser in current working directory
* Type a few characters that begins filename ("`fi`")
* Press TAB to autocomplete filename/directory as much as possible ("`file`")
* Press TAB again to see a list of files that complete ("`file1.txt`, `file2.txt`")
* Type 2 and TAB to complete to `file2.txt`
* Press ENTER to open file.

When I try the same action with this extension installed, the TAB toggles between the file select region and two other regions I don't understand. Video demo below.

https://github.com/bodil/vscode-file-browser/assets/274093/d2cac39b-30ca-465e-b82d-f3dfe0884a28

And it doesn't autocomplete the part of the filename that matches (e.g. expand "fi" to "file"). It also does not complete directory names (e.g. typing "adirectory" in the example above yields "no matching results") . Also, I would expect just pressing TAB in a blank file browser would show me all files (e.g. matching all files)

What am I doing wrong?

Start by reproducing the file-selection workflow described in the issue with vscode-emacs-mcx enabled, paying particular attention to TAB focus changes and directory matching. Done means TAB expands partial names, lists matching files, completes directories, and shows all files from a blank selector without the reported region toggling.

Written by the indexing model from the issue text.