‘Save Image’ & ‘Save Video’ icons missing.

(iPhone X, iOS 12.1.3 & 12.1.4)

It was possible, from within the Files app, to save an image to Photos, using the Save Image icon in the context menu. Ditto for videos, using the Save Video icon. Now both options are gone from the context menu, when interacting with an image or video (within Files). What is the likely cause?

This does not involve an update. I noticed this issue before updating to 12.1.4. I updated today, and the problem persists. I tried rebooting the device, both before and after the update, and the problem persists.

Attached photos are to show the missing icons.