Thanks Ramachandra. Unfortunately, all methods in the first link did not work (e.g. I tried wsl --shutdown and disabling fast startup), and the second link answered the opposite of my question (connect to Windows MongoDB from WSL).
As a guess, is the issue related to how mongodb protocol is configured? For example, If I run python -m http.server --bind 127.0.0.1 8000 in WSL and visit “http://127.0.0.1:8000” in Firefox on Windows, everything works. I can say that localhost forwarding of WSL works for HTTP protocol. Is it possible that MongoDB network protocol does have the same support?