I got error "Access denied", but I didn't change the password.
if it's still miner1, you should really change it. (passwd m1)
Also, use command history
This'll show you if anything has been done during the "access denied" period.
I checked command history (with command: history) and everything looked fine (no command for password change).
The miner is hidden behind a firewall so i am OK with this default password ...