Hi there,
home assistant os is running on a raspberry pi 5 and works pretty fine. I added the HA addon Advanced SSH & Web Terminal and there I can easy enter the console. Fine.
But when I try to connect via putty, he ask for login as, where I enter root but after entering the password, I get a access denied back.
So I went back to the Advanced SSH & Web Terminal and reset the password by passwd to a very simple one.
Yes check the config for ssh in addons. The username will be there and its likely not to be root. You will have had to set username and password.
If you have set it to root then set it to something else in the addon.