configure f5 login using AD

Looking back at previous posts, it looks like you're using the f5admin account as the Bind account. This is the account that logs into the AD and performs the query, so it needs enough permissions to do so.

Are you also using this same account to attempt to log into the BIG-IP management GUI?

In any case, the LTM log is just telling you that it failed. We know that. You really need to look at a WireShark capture of the LDAP traffic to see why it's failing.