After reporting LB-1757: https://tickets.metabrainz.org/browse/LB-1757 I went investigating why this might be and came across a hanging POST request when the user seeks to load their profile. The user webpage just displays a blank nothing and after a minute or so the user profile and listens appears (see screenshot)

How to replicate:
Use Inspect Elements in your browser on Network tab, login to listenbrainz, wait for redirect to your user page and view how the various assets load on the page.

You should see a POST request initated by Loader.ts:24 that takes over 40 seconds to load to return a 200 status (see screenshot) once this resolves the content on the webpage is properly displayed to the user.

OS: Linux Ubunutu
Browsers affected: Firefox, Brave, Chromium (latest versions)