Cannot update Applications

Check your purchases history. Do the apps that need updating show there? If not, they were downloaded using a different Apple ID. One option is to delete the app and download the app again using your current Apple ID.

Purchase History Review.  

If the apps do show in your purchases history, try signing out of the App Store/iTunes, restarting the device, and then signing back in. See if you can do the updates.

If necessary, contact iTunes Support for assistance. See the Apple Support articles below for contact information.   

iTunes Support – world wide 

Apple Support schedule phone call       

If necessary, try Twitter

https://twitter.com/AppleSupport.          People have posted it may take an hour or more to get a response.

This is your problem. See What to do when the Mac App Store shows a different Apple ID for software updates https://www.macworld.com/article/3267709/mac-app-store-apple-id.html. This document refers to a prior owner (use the discussion in it this is your situation), but is also applies to cases where a current owner's old Apple ID is the problem. The discussion below relates to the second possibility.

Basically, If an app is purchased/downloaded using one Apple ID, then you can't update it with a second Apple ID. The app is inextricably linked to the first Apple ID. You'll have to delete if from the first Apple ID and purchase/download it again with the second Apple ID unless you set up family sharing (see below).

You can set up family sharing between the IDs to share purchases made with them. See:

Family Sharing  https://support.apple.com/en-us/HT201060

Set up Family Sharing https://support.apple.com/en-us/HT201088

Have you fixed your problem?

Did you try what I posted above to include contacting iTunes Support if necessary?

The iCloud data should sync back, but it may take a couple of days or more for the sync to complete.