Mobile-Safari stopped asking me to update passwords I use a wifi hotspot where, after I connect, I have to fill in my username and password in a loginscreen. 
My username stays the same, but the password changes quite often. 

Safari used to detect when I entered a different password, and offer me to update my saved password. Now not any more...

How do I enable this?
Go to Settings→Safari→'Passwords and AutoFill' and enable 'Name and Passwords'.