You need to do the following through ASDM with that priv 15 user, then the Read-only and Monitor-only users will begin to work:
Currently, logging in with a user of privilegel 15, navigate to Configuration > Device Administration > AAA Access > Authorization. There is a button "Predefined User Account Privilege". If you select this and apply this, it wil set a series of commands to a lower privilege based on what ASDM needs to authorize that user for either Read Only or Monitor Only access.
Then you would need to create a new user account with privilege 5 access so that ASDM is read only, or create a new user with privilege 3 for monitor-only access.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...