I’ve been away for about a week and now cover art is consistently failing to load in ListenBrainz (but is fine in MBZ). It’s a pretty standard CORS error; I can reproduce in multiple browsers, though the console error has slightly different wording.
Access to fetch at ‘https://coverartarchive.org/release/abf82a62-3ff7-48f9-8944-63694acaf1f1’ from origin ‘https://listenbrainz.org’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the resource with CORS disabled.