I signed out from my old AppleID and it was removed from my iPhone. However, the iPhone still asks for the old AppleID and password when downloading and updating apps.
How can I solve this?
If an item is purchased with an Apple ID (even if it is a free item) it can only be updated using that same Apple ID.
For example, if you downloaded the Facebook app using the Apple ID "firstname.lastname@example.org" and you now use the Apple ID "email@example.com" then you must either update the app using "firstname.lastname@example.org" or delete and re-download the app using "email@example.com".