Incorrect assumption about user's Pod and URL (incl. path) -- inconsistent UI behaviour for SolidOS

I'm experiencing this issue since the beginning of me attempting it (i.e. Feburary 2022). It actually happens on all status of mashlib -- SolidOS Web App, https://solidcommunity.net and my custom CSS with mashlib recipe set up.
It is most noticeable with a CSS set up, compared to https://solidcommunity.net (or other similar services). This is because on https://solidcommunity.net, each user's pod is on a (sub-)domain (hostname), not on a sub-directory under a hostname.

My CSS server has user pods in different (sub-)directories, and there is no "root" pod account. Assume the server's address is https://MY_SERVER, and the user is MY_USER.

Open https://MY_SERVER, after logging-in, the UI is (seemingly) in the expected state, as seen in the figure below.

However, the user is not redirected to its own pod (https://MY_SERVER/MY_USER/), but is still on the root of the server (https://MY_SERVER/). This can be verified by clicking on "your storage", which will list all files and folders under the root folder https://MY_SERVER/ (in this set-up, there is only one account, i.e. MY_USER).

This is not very intuitive, but still acceptable.

After manually navigating to https://MY_SERVER/MY_USER/, the UI appears as if it's browsing the folder only:

However, because this is the actual pod of the user MY_USER, I would expect it to show the same set of navbar/menubar as seen in the first figure, with "your stuffs" and other menu items.

This can (almost) be obtained by clicking on "your stuff" from the user icon's menu (on the top-right corner).

However, this is still not exactly the same as in the first figure: the navbar with icons is still missing (see the figure below which highlights the missing part). I did not find a way to make them appear.

So, in conclusion, it seems mashlib is only showing the full UI (as seen in the first figure) when on the root of the hostname (e.g. https://MY_SERVER/). This has an assumption that the user pod is on the hostname, which is incorrect in many CSS set-ups.

Reproduce the behavior in the SolidOS Web App and the mashlib recipe using a pod under a sub-directory rather than the server root. Compare the UI at https://MY_SERVER/ and https://MY_SERVER/MY_USER/ after login, including the user menu and navbar. Done means the user's pod URL consistently shows the expected full UI and storage links.