Can't create private shared folders from GUI

Context: I want to create a private folder between myself and another person.

I click on the icon in the system tray and click the "New private folder" button. I type in the username of the other person I want to share the folder with, and then I either press Enter or press the icon (I've tried both).

After that, the K:\ drive is opened in a new Explorer window. However I can't find any sign of the private shared folder, there is no visible K:\private\user1,user2\. From the user's perspective it looks like it just opens K:\ drive in Explorer and does nothing else.

Trying to create the folder in Explorer with the intention of renaming it to user1,user2 didn't work either, as it was removed as soon as "New folder" was created. (I know the private shared folder is supposed to implictly exist.)

(I was able to get it to appear by running keybase fs mkdir /keybase/private/user1,user2/test in cmd)

I'm running Windows 10. I don't know if this happens on other platforms (I could test on Linux at some point).

Reproduce the system-tray "New private folder" flow on Windows 10 and compare it with the working keybase fs mkdir /keybase/private/user1,user2/test command. Inspect the GUI entry point that handles the username submission and opens Explorer. Done means the private shared folder is visible under K:\private\user1,user2\ after pressing Enter or the icon, without using the CLI.