"Restore in Progress: An Estimated [XX] will be required to finish restoring your apps and data"

Three days ago, I migrated to a new iPhone, and restored from an iCloud backup. The setup completed and the phone appears to be working [mostly] normally, except:

• A lot of my app settings didn't seem to come over - I had to re-log in or reconfigure all my apps. I'm not sure if this is related to the following issue:
• In Settings, a message right under my name and Apple ID information says:

Restore in Progress

An estimated [1.2 GB] will be required to finish restoring your apps and data.

There aren't any apps that appear to be waiting to download. The amount of remaining data fluctuates, from 100 MB to 500 MB to 1.2 GB, back and forth.

There are numerous threads where Apple Community Specialists mis-diagnose the issue as being related to inadequate storage. (For example, here, here.] Or they mis-diagnose as the device being frozen during the restore. (For example, here.)

This is not a storage issue, either on the phone (only 64 GB out of 128 GB is used), or in iCloud (only ~50GB out of 200 GB is used). The phone is not frozen. This is not a network issue, as I have a strong WiFi connection and very fast broadband.

If it sheds any additional light on the matter, when I leave Wifi, I get the pop-up dialog telling me:

Use Wi-Fi to Restore

A Wi-Fi connection is required to download your apps and media.

Later Use Wi-Fi

And the Settings dialog says:

Restoring from iCloud will resume when this iPhone is connected to Wi-Fi.

So, I think it has just stopped downloading data and needs to know to try to resume it. Note that the phone won't back up to iCloud until the stuck restore finishes. And according to this thread, software updates won't install either.

Any suggestions?

Thanks!