The password is the same for main and sub domains. The problem is solvable if I disable multisite mode – I can then log into main domain and admin. If I enable multi I can log into the subdomains but not main/admin. The password is the same.
I can make the site work by using Categories instead of subdomains, but I lose the custom look of each sub. WP-CONFIG.PHP is properly defined as is .HTACCESS.
It’s just weird.