I went to the App Store on an iPad Air 2. From there, I tried to update Numbers. I was asked to provide a password for the iTunes Store. I assumed this was the same password as for my AppleID, but it was refused. After two more attempts, I gave up.
I tried to login to icloud.com in Firefox, and my attempt failed. I tried to login to icloud.com from Safari and I was successful. This told me that I was using the correct password and that I hadn’t locked myself out (yet).
Out of curiosity, why did my attempt from Firefox fail? There was some message, but Firefox covered it up with a list of login credentials (containing one item) for icloud.com before I could read it. I thought it said something about my password needing to be reset, but I’m not at all sure, and I subsequently logged in from Safari.
More seriously, what password is the iPad looking for when I try to download the Numbers update? It shows my AppleID in the Accounts pane where it offers me a Numbers update, so I assume it wants the password associated with my AppleID, but then verification fails. Any help? Thanks.