Identify precisely the overload error by number (probably 503) and message.
On this error only, retry fetching the release again.
For 5 times, maximum, before giving up, and tell the user the MB server is overloaded at the moment.

https://hydrogenaud.io/index.php/topic,70623.msg919228.html#msg919228
https://community.metabrainz.org/t/rate-limiter-has-changed/14253/6?u=jesus2099