I’m the author of the topic Unable to login after 8.4.2 update - have you guys put this to work.
Because I had a working configuration, update broke it, and apparently SuiteCRM is clueless about what is going on. So have you figured a fix?
If not, I also invite you to participate on the GitHub Issue about this.
It’s surreal to me that an error introduced by an update is persisting through two versions.