We faced an issue with version OSS 3.42.0-01 where when a specific header becomes too big, we are getting an HTTP400, and the site stops.
The Header is part of our authentication process via the oauth2-proxy, which gets the Identity Provider Security Groups back and then tries to deliver those to Nexus. So, when we disable the groups, NEXUS is stable.
This is a workaround, but you should check why it can’t handle huge Headers and give responses with HTTP400.