[Observium] LDAP Issue

Hi - I'm trying to configure LDAP authentication according to the authentication page on the observium website, but it doesn't appear to be working. If I try a login that should work or one that doesn't work the result is the same - the login fields blank out again with no error message.

Just wondering how I go about fixing this? Alternatively is there any log files that can offer some explanation as to why it's not working? I've had a look but can't find any.

Thanks, Quentin